<![CDATA[Diving liveaboard in Thailand and Myanmar - BLOG]]>Wed, 13 May 2026 17:13:23 +0700Weebly<![CDATA[The Paper Nautilus (Argonaut): The Ocean’s Most Fragile Cephalopod]]>Tue, 12 May 2026 05:00:00 GMThttps://www.thesmilingseahorse.com/blog/the-paper-nautilus-argonaut-the-oceans-most-fragile-cephalopod
Paper Nautilus Argonaut Blackwater diving andaman sea Thailand Myanmar Scuba Diving Liveaboard Cruisea

All about the Paper Nautilus

Paper Nautilus Argonaut Blackwater diving andaman sea Thailand Myanmar Scuba Diving Liveaboard Cruisea
Female Paper Nautilus have this distinctive shell on this back
Female Paper Nautilus drifting during blackwater dive
Argonauts can be found itching a ride on passing salp during blackwater dive
We first encountered this incredible little creature while Blackwater diving in 2017. At the time, we had absolutely no idea what we were looking at. ​
The first Argonaut we encountered was apparently a female, as male are 10 times smaller (rarely passing the size of 2cm) and dont have a shell.

Since then, we’ve been lucky enough to spot Paper Nautiluses many more times — including during blackwater dives in the Similan Islands — and finally managed to capture a few decent photos.
After some research, we discovered this strange and beautiful animal is called a Paper Nautilus, also known as an Argonaut.
Despite the name, the Paper Nautilus is not actually related to the true nautilus. It belongs to the octopus family and is one of the ocean’s rarest pelagic cephalopods

What is a paper Nautilus?

The Paper Nautilus (Argonauta argo) is a species of open-ocean octopus found in tropical and subtropical waters around the world, including the Andaman Sea, Thailand, Myanmar, and the Similan Islands.

The delicate white “shell” carried by females is not a true shell like a nautilus shell. Instead, it is a thin egg case secreted by the female using two specially adapted arms.
​
The female uses this paper-thin structure to:
  • Protect her eggs
  • Control buoyancy
  • Shelter herself in open water

Male Argonaut are tiny — often less than 2 cm long — and do not produce a shell at all.

​One of the Weirdest Mating Systems in the Ocean

Argonaut octopus carrying egg case in the Andaman Sea
Female Paper Nautilus riding a Jellyfish
Argonaut reproduction is famously bizarre.
One of the male’s specialized arms acts as a reproductive organ called a hectocotylus. During mating, this arm detaches from the male’s body and remains inside the female to fertilize her eggs. The female then secretes the papery shell with the tips of two tentacles. She lays her eggs inside the paper shell and watch them until they are ready to hatch and her job is done.
For many years, scientists thought these detached arms were actually parasitic worms because nobody had ever seen a complete male Argonaut.

Nature is weird sometimes.

​The Paper Nautilus and Its Incredible “BCD”

One of the most fascinating things about the female Paper Nautilus is its ability to control buoyancy.
Argonauts are the only known octopuses capable of trapping air from the ocean surface inside their shell-like egg case.
The female swims to the surface, captures a small air bubble, seals the opening using her arms, then descends back into deeper water.
This trapped air acts almost like a diver’s BCD (buoyancy control device), helping the Argonaut achieve neutral buoyancy and drift effortlessly through the open ocean.
​It’s one of the most unique buoyancy adaptations in the marine world.
Paper Nautilus strange buoyancy technics
Paper Nautilus Swimming

5 Amazing Facts About the Paper Nautilus​

Picture
This pelagic octopus uses jet propulsion to escape faster
🐙 1. The “shell” isn’t a shell at all!
Female paper nautiluses don’t actually have shells; they build a delicate paper-thin case just to store their eggs. It’s basically the ocean’s most elegant Tupperware.

🐙 2. The male is so tiny he looks like he forgot to evolve.
Females can grow up to 20 times larger than males. A male paper nautilus is hard to tell from other octopus you see on blackwater dives.

🐙3. They can “glide” underwater using jet propulsion .Like other octopuses, Paper Nautiluses swim using jet propulsion, expelling water through a siphon to move surprisingly fast through open water. Females may also use their delicate egg case to stabilize themselves while drifting in ocean currents.
🐙 4. Paper nautiluses ae true pelagic hitchiners
They grab floating objects—seaweed, jellyfish, even trash—to ride ocean currents and save energy. They’re the backpackers of the sea, but with much better fashion sense.

🐙 5. They can transform into tiny air-sailors.
​By trapping air inside their paper-thin case, females can float at the surface like miniature balloons, rising and falling like they’re on a tiny ocean elevator.
black water diving with a male paper nautilus
Male argonauts can be hard to differentiate from other octopus
Paper Nautilus Argonaut andaman sea Thailand
Male Paper Nautilus are much smaller and do not carry a shell

Where Can You See a Paper Nautilus?

Paper Nautiluses are rarely seen during normal scuba dives because they live in the open ocean.

The best chance of encountering one is during:
  • Blackwater diving (Pelagic night dives)
  • Night dives on remote offshore locations close to deep waters
  • in tropical waters
Rare cephalopods on blackwater dive hiding in salp
They are pelagic hitchhikers, often found riding on salp chains like in this photo

​Why Divers Love the Paper Nautilus

For underwater photographers and blackwater divers, finding an Argonaut is a bucket list encounter.
They are incredibly delicate, rarely seen, and completely alien-looking.
Watching one drift through the water while carrying its paper-thin egg case feels more like encountering a creature from another planet than a marine animal.
]]><![CDATA[Trip Report | North Andaman | 7th to 14th April, 2026]]>Fri, 24 Apr 2026 08:30:17 GMThttps://www.thesmilingseahorse.com/blog/trip-report-north-andaman-7th-to-14th-april-2026
The MV Smiling Seahorse liveaboard boat cruising through the blue waters of the North Andaman Sea, Thailand, during a dive expedition.
The ocean doesn’t follow a plan — it sets the pace.
​
Over the course of this North Andaman expedition, each dive unfolded with its own rhythm, from granite boulder fields to fish-packed pinnacles, where currents, schools and encounters constantly reshaped the experience.

Day 1 – Departure from Khao Lak to the Similan Islands

We departed from Tap Lamu Pier in Khao Lak with our guests from France, heading north toward the Similan Islands. Calm seas and a soft golden light set the tone as we settled into life on board, preparing for the days of diving ahead.
A crew member named Boom driving a blue and white inflatable dinghy on calm waters in Similan National Park.
Boom Driving the Dinghy | Denis Cadon
Divers gathered around a table on a liveaboard deck for a sunset dive briefing in Thailand.
Guests and staff go over the dive plan for the next site in Similan National Park.

Day 2 – Similan National Park

At Shark Fin Reef, the first dive was the perfect warm up with a classic Similan landscape of submerged granite formations. Two-tone dartfish hovered above the sand while a hawksbill turtle cruised by. Clown triggerfish and a whitetip reef shark added movement, while dogtooth tuna patrolled the blue. On the reef, Gymnodoris (lemon gymnodoris), Caloria indica, six-striped soapfish, andaman sweetlips and juvenile chiseltooth wrasse appeared among schools of blue-and-gold fusiliers and surgeonfish. Our divers were also able to recover a knot of abandoned fishing gear that was floating at the surface- we always give back to the ocean when we can. ​
A Hawksbill sea turtle swimming through deep blue water in the Similan Islands, Thailand.
A graceful Hawksbill sea turtle captured mid-glide through the pristine blue waters of the Similans. | Denis Cadon
A Giant Moray Eel peering out from a colorful coral reef structure in the North Andaman Sea.
This Giant Moray Eel found a perfect hiding spot among the colorful corals and granite boulders of North Andaman. | Denis Cadon
A colorful Caloria indica nudibranch with orange, blue, and white cerata crawling on a red sponge in the North Andaman Sea.
The vibrant colors of a Caloria indica nudibranch stand out against the red reef sponges during a macro dive in the North Andaman. | Denis Cadon
At Boulder City, the energy picked up. The “gang” of bluefin trevallies and longnose emperors hunted through a dense school of batfish and barracuda. Around the reef, bignose unicornfish, humpback unicornfish and bluespine unicornfish cruised effortlessly, some stopping to show off their colours to a potential mate. Macro life revealed long-snouted crinoid shrimp, commensal crinoid shrimp, false cleaner wrasse, Midas blenny, Smith’s fang blenny and both adult and juvenile blue-lined angelfish.
A tiny Long-Snouted Crinoid Shrimp (Allogalathea elegans) perfectly camouflaged within the feathered arms of a crinoid.
Hidden in plain sight: The intricate patterns of a Long-Snouted Crinoid Shrimp help it blend seamlessly with its host in the North Andaman. | Denis Cadon
A large coral head decorated with colorful, spiraling Christmas Tree Worms (Spirobranchus giganteus) on a reef in the Similan Islands.
A large brain coral head decorated with colorful, spiraling Christmas Tree Worms (Spirobranchus giganteus) on a reef in the Similan Islands.
At Hideaway, the dive slowed down with octopus, Glossodoris cincta, garden eels and squat shrimps tucked into the reef. A psychedelic batwing slug stood out among the colours, while fusiliers, butterflyfish and surgeonfish filled the water column.
The day ended with a sunset dive at Honeymoon Bay, where we found a brave longfin comet fish hiding inside the reef, a Jenkins whipray rested on the sand, and dragonets darted between coral heads. Marbled grouper, bluefin trevally, octopus, moray eels and another psychedelic batwing slug completed a calm and atmospheric dive, with brown tangs grazing quietly in the fading light.
A wide-angle view of a diverse coral reef featuring table corals, soft corals, and a diver in the background in the North Andaman Sea.
A thriving underwater garden: Table corals and vibrant soft corals create a stunning backdrop for divers exploring the healthy reefs of the Similan Islands. | Denis Cadon
A tiny Psychedelic Batwing Sea Slug (Sagaminopteron psychedelicum) with intricate white and green patterns on a reef in Thailand.
A true macro treasure: The rare and stunning Psychedelic Batwing Sea Slug is a bucket-list find for many divers in the North Andaman. | Denis Cadon
A close-up of an octopus peeking out from a small crevice within a hard coral reef structure.
Keeping a watchful eye: An octopus masterfully blends into the coral crags of the Similan Islands, waiting for the perfect moment to move. | Denis Cadon
A bright yellow Longnose Butterflyfish swimming past pink soft coral trees on a reef in Similan National Park.
A splash of color: This Longnose Butterflyfish stands out beautifully against the lush soft coral gardens of the Similan Islands. | Denis Cadon
A dark Comet Fish with white spots tucked into a rocky crevice on a coral reef in the North Andaman Sea.
Finding the shy ones: A stunning Comet Fish displays its starry patterns while hiding among the reef crags of North Andaman. | Denis Cadon

Day 3 – Similan National Park

At Deep Six, strong currents brought action. A whitetip reef shark passed by, alongside a green turtle and bluefin trevallies. Macro highlights included Glossodoris cincta, baby Moridilla brocki, clown triggerfish and a striking blue dragon.
A colorful Glossodoris cincta nudibranch with a distinctive dark border crawling across a sandy seabed in Thailand.
A macro highlight: This Glossodoris cincta nudibranch showcases its intricate patterns while traversing the white sands of the Similan Islands. | Denis Cadon
Two bright orange anemonefish peeking out from the protective tentacles of their host sea anemone in the North Andaman Sea.
A classic reef scene: Curious anemonefish dart between the swaying tentacles of their home in Similan National Park. | Denis Cadon
A Spearing Mantis Shrimp peeking out from its burrow in the reef floor, showing its large, complex eyes.
Peer into the burrow: The incredible eyes of a Spearing Mantis Shrimp watch carefully as we explore the reef floor in North Andaman. | Denis Cadon
At West of Eden, the reef was alive with detail. Spearing mantis shrimps and squat shrimps occupied the substrate, while McCosker’s flasher wrasse flickered in the water column. Schools of emperors, hawksbill and green turtles, batwing psychedelic seaslugs, multibar pipefish and Andaman jawfish created a rich and varied dive. Fusiliers, snappers and parrotfish filled every layer.
At Elephant Head Rock, dramatic swim-throughs revealed ribbon eels, Andaman jawfish, Glossodoris cincta and bluestreak gobies. Schools of trevallies, sweetlips and fusiliers added movement to the rugged topography.
Massive orange and yellow gorgonian sea fans clinging to a rocky reef wall in the North Andaman Sea.
A wall of life: Stunningly large gorgonian sea fans stretch out into the current along the granite walls of the Similan Islands. | Denis Cadon
Three Moorish Idols with their distinctive yellow, black, and white bands swimming vertically against a deep blue reef backdrop.
Elegance in motion: A trio of Moorish Idols showcases their long dorsal filaments while cruising the healthy reefs of Similan National Park. | Denis Cadon
A massive, shimmering school of transparent Glassfish swarming around a colorful coral reef wall in the North Andaman Sea.
Underwater fireworks: A dense school of Glassfish shimmers like silver as they flow over the vibrant soft corals and sea fans of Similan National Park. | Denis Cadon
Later, we stepped ashore at Island Number 8, where a short climb led us to the iconic viewpoint overlooking Donald Duck Bay — a sweeping panorama of turquoise water framed by granite boulders, offering a rare moment to take in the Similan Islands from above.
Four smiling guests standing on a large granite boulder overlooking the turquoise bay and white sand beach of Similan Island No. 8.
Making memories at the top: Our guests enjoying the panoramic views from the famous Donald Duck Rock viewpoint. | Denis Cadon
High-angle scenic view of the crystal-clear turquoise waters and lush tropical greenery of Donald Duck Bay in the Similan Islands.
Perfection in blue: The iconic view of Donald Duck Bay, where white sands meet the vibrant reefs of Similan National Park. | Denis Cadon
The night dive at Turtle Rock brought intense activity. Snappers hunted in the beams of our lights while skeleton shrimps, decorator crabs, ornate sapsucking slugs, tiger cowries, whip coral shrimps and anemone hermit crabs covered the reef. A spearing mantis shrimp enjoyed an all you can eat shrimp buffet in our torchlight while soft coral ghost gobies, clearfin lionfish, feather duster worms, Gosliner flatworms, Harpiliopsis shrimp, Hyman’s flatworm, bicolor flabellina and Glossodoris cincta completed the scene.
A large Map Pufferfish swimming over a dark reef alongside a school of small silver fish during a night dive in the Similan Islands.
A large pufferfish glides through the darkness, surrounded by shimmering baitfish on a healthy reef in Similan National Park. | Denis Cadon
A close-up of diverse hard and soft corals illuminated during a night dive in the Similan Islands, Thailand.
The reef transforms after dark, revealing the intricate textures and deep colors of the hard corals in Similan National Park. | Denis Cadon
A detailed macro shot of a Glossodoris cincta nudibranch with its signature dark, ruffled border on a rocky reef.
Macro perfection: This Glossodoris cincta nudibranch stands out against the rugged reef floor of the North Andaman Sea. | Denis Cadon

Day 4 – Similan National Park

At North Point, the dive opened with a balanced mix of pelagic movement and reef life. Dogtooth tuna cruised past in the blue while a turtle moved calmly along the reef. Schools of barracuda held their position in the current, creating a steady backdrop of motion.

​Closer to the reef, the scene became more detailed: fringelip blenny peeked from small crevices, juvenile lionfish drifted cautiously between coral heads, and sand lizardfish rested motionless on the bottom. Schools of lunar fusiliers and neon fusiliers streamed across the reef, joined by striped surgeonfish grazing steadily, while butterflyfish and damselfish filled the shallower sections.
A scuba diver named Pascal exploring the deep blue waters of Similan National Park, Thailand.
Into the abyss: Pascal takes in the incredible visibility and deep blue hues that make diving in the Similans world-famous. | Denis Cadon
A wide-angle view of diverse corals and tropical fish, including a Monocle Bream, on a sunlit reef in the North Andaman Sea.
Life on the reef: A Monocle Bream swims past a fan-shaped coral structure during a sun-drenched afternoon dive in North Andaman. | Denis Cadon
At Christmas Point, the energy shifted into a true hunting scene. Bluefin trevallies and longnose emperors formed the core of the action, working together with rainbow runners in tight formations — a classic “Christmas tree” moment as they moved across the reef in coordinated bursts. Around them, schools of fusiliers and snappers reacted instantly, compressing and expanding in response to the pressure, constantly reshaping the water column. Wrasses and parrotfish pecked at the reef, weaving through the chaos.
A vibrant Checkerboard Wrasse showing its neon green, pink, and blue patterns while swimming over a rocky reef in the Similan Islands.
A kaleidoscope of color: This Checkerboard Wrasse puts on a brilliant display as it patrols the sunlit reefs of the North Andaman Sea. | Denis Cadon
At Three Trees, the landscape opened into sandy patches and coral bommies, creating a more spacious and atmospheric dive. A Kuhl’s stingray rested half-buried while the glassfish filled every crevice of the reef and nearby bommies. 

In the blue, a tornado of barracuda briefly formed, tightening into a spinning column before slowly dispersing again — a fleeting but striking moment. Oriental sweetlips hovered near coral heads, while yellowfin emperor and brown-marbled grouper stayed close to structure.
​
Large barrel sponges hosted sea fans growing along their sides, with spotted garden eels scattered across the sand. Yellowmargin triggerfish guarded their nests, adding bursts of territorial energy, while bignose unicornfish cruised above.
Barrel Sponge Denis Cadon Andaman Scuba Diving Liveaboard Thailand
A titan of the reef: This ancient Giant Barrel Sponge adds a dramatic splash of red to the underwater landscapes of Similan National Park. | Denis Cadon
The final dive at Koh Bon brought us fully back into the blue. A Napoleon wrasse appeared out of the current, followed by dogtooth tuna cutting across the reef. Schools of barracuda, batfish and rainbow runners moved constantly through the site, with bluefin trevallies weaving between them.
A scuba diver floating on the surface with an orange signaling buoy, waiting for a boat pickup in the deep blue waters of the Andaman Sea.
Mission accomplished: A diver signals the boat after an incredible drift dive through the crystal-clear waters of Similan National Park. | Denis Cadon
A large Map Pufferfish (Arothron mappa) swimming over a rocky reef next to a pale pink soft coral tree in Thailand.
Reef residents: A distinctive Map Pufferfish glides past vibrant soft corals during a dive in the North Andaman Sea. | Denis Cadon

Day 5 – Koh Bon & Koh Tachai

At Koh Bon Pinnacle, the dive delivered one of the highlights of the trip: a bull shark appearing briefly in the blue, powerful and unmistakable. A hawksbill turtle hid under an overhang, while yellowback fusiliers filled the water column. Bluefin trevallies hunted actively, and a cluster of Spanish dancer eggs clung to the reef. Batfish hovered mid-water while a guitarfish rested on the sand, almost blending into the seabed. Brown-marbled groupers stayed close to the reef, completing the scene.
A tiny green Sap-Sucking Slug (Costasiella sp.) camouflaged against algae on a reef in Thailand.
Hidden beauty: A macro look at a Sap-Sucking Slug, a master of disguise in the lush underwater gardens of the Similan Islands. | Denis Cadon
A massive orange gorgonian sea fan standing prominently against the deep blue water of the North Andaman Sea.
Majestic structures: This expansive sea fan highlights the healthy, current-swept walls found throughout the Similans. | Denis Cadon
A vibrant school of yellow snappers swimming beneath bright pink soft coral trees on a rocky reef.
A riot of color: Yellow snappers create a stunning contrast against the pink soft corals in Similan National Park. | Denis Cadon
A large Spiny Lobster peeking out from its rocky shelter on a coral reef in the Andaman Sea.
Reef guardians: A Spiny Lobster keeps a watchful eye from the safety of its coral crevice in North Andaman. | Denis Cadon
At Koh Tachai Pinnacle, schools of batfish gathered in impressive numbers, mixing with giant trevallies, bluefin trevallies and bigeye trevallies. Brown-marbled groupers moved between boulders while schools of bluestreak fusiliers, neon fusiliers and yellowback fusiliers streamed across the pinnacle.
​The following dive at Koh Tachai Pinnacle brought great barracudas patrolling the edges, alongside more bluefin trevallies and giant trevallies. We spotted some lobster hiding in the cracks as longnose emperors moved confidently around us. A Juvenile Spanish dancer and Hypselodoris maculosa added colour to the substrate as Boer's batfish and a group of teenage longfin batfish hovered in the current, creating a layered mid-water scene. Spotted hypselodoris appeared along the reef, reinforcing the macro diversity.
A large, silver Batfish swimming toward the camera, perfectly framed by the sun's rays in the deep blue waters of the Similan Islands.
A moment of grace: This curious Batfish drifts effortlessly through the crystal-clear waters of Similan National Park, illuminated by the midday sun. | Denis Cadon
A small, bright orange and red sea star resting on a rocky reef floor in the Similan Islands.
Spotted on the seafloor: A vibrant red sea star adds a pop of color to the granite underwater landscapes of Similan National Park. | Denis Cadon
A powerful Giant Trevally (Caranx ignobilis) swimming through the deep blue water of the North Andaman Sea.
Power in the blue: A majestic Giant Trevally patrols the current-swept reefs, showcasing the impressive predator life of North Andaman. | Denis Cadon
The night dive at Koh Tachai Reef was intense from start to finish. Blacktip reef sharks were present from the first minute to the last, constantly cruising through the lights. Anemone hermit crabs, blunt decorator crabs and ornate sapsucking slugs dotted the reef, while an unidentified flatworm added another mysterious element to the dive.

Nighttime adrenaline: Encountering Blacktip Reef Sharks under the cover of darkness at Koh Tachai is a highlight of the Andaman experience. | Denis Cadon

Day 6 – Surin National Park

A snorkeler's head visible in the water nestled between large granite boulders at Surin National Park.
Hidden coves: Exploring the dramatic rocky coastlines and pristine waters of Surin National Park. | Denis Cadon
A snorkeler wearing a bright orange life vest and mask floating in clear turquoise water at the surface.
Surface wonders: The vibrant turquoise waters of the Surin Islands offer world-class snorkeling right from the boat. | Denis Cadon
At Hin Kong, macro life took center stage. Cadlinella ornatissima, Robastra gracilis, squat shrimps, porcelain crabs and Hyman’s flatworms were scattered across the reef, turning the dive into a slow and detailed exploration. During our surface intervals, we also had lovely snorkelling excursions to the coast of these stunning islands. 
A dark Hyman's Flatworm with an orange-gold ruffled border crawling over a textured, sandy reef floor in the Similan Islands.
Elegance in miniature: The striking ruffled edges of a Hyman's Flatworm create a beautiful contrast against the rugged seabed of Similan National Park. | Denis Cadon
At Yellow Rock, we witnessed a full colour spectrum in our encounters. Spotted hypselodoris, Hypselodoris bullocki, allied cowrie and bicolor flabellina stood out against the reef. A juvenile shaded batfish tried to blend in nearby, while a pygmy seahorse remained perfectly camouflaged. Silver Andaman sweetlips added contrast, moving slowly along the reef.
A Juvenile Shaded Batfish with a tall, black body and vibrant orange trim swimming near a colorful reef crevice in the Similan Islands.A rare find: The striking silhouette and bold orange highlights of a Juvenile Shaded Batfish stand out against the red sponges of Similan National Park.
At Torinla, two Napoleon wrasses stole the show — one large female and an impressive, massive male cruising slowly across the site, completely unbothered by divers. A hawksbill turtle munched away at the corals, equally unimbressed by the divers while a tiny juvenile pufferfish tried to hide in the sand on the reef’s edge. ​
A tiny, vibrant yellow Cadlinella ornatissima nudibranch with pink-tipped nodules crawling on a textured reef in Thailand.
Small wonders: This brightly colored Cadlinella ornatissima nudibranch is a prized find for macro photographers in Similan National Park.
A detailed shot of a Lionfish with its striped body and venomous fins displayed, swimming near red sponges on a rocky reef.
Elegant predator: A Lionfish displays its ornate fins as it patrols the healthy, sponge-covered reefs of the North Andaman Sea.
A Scribbled Filefish with neon blue patterns swimming over a colorful coral reef, with a school of fusiliers in the background.
Electric patterns: The Scribbled Filefish stands out with its intricate blue markings against the diverse reef life of Similan National Park. | Denis Cadon
A macro shot of a spotted Porcelain Crab tucked safely among the stinging tentacles of a sea anemone.
Symbiotic safety: A tiny Porcelain Crab finds shelter within the protective tentacles of an anemone in the North Andaman Sea. | Denis Cadon
The night dive at Ao Pakkad delivered one of the strongest macro moments of the trip. Seven harlequin shrimps were found across the site, alongside Flabellina exoptata, Glossodoris atromarginata, complex marble shrimps, Conus geographus and blacktail Zanzibar urchin shrimp. Around them, file fish, crabs, shrimps and nocturnal reef life created a dense and vibrant night scene.
A pair of Harlequin Shrimp (Hymenocera picta) with pink and blue spots feeding on a red sea star on a rocky reef.
A rare macro find: Harlequin Shrimp display their intricate patterns while perched on a sea star in the Similan Islands. | Denis Cadon
A vibrant purple and orange Flabelina exoptata nudibranch clinging to a delicate hydroid against a dark background.
Neon of the reef: The striking colors of a Flabelina exoptata nudibranch stand out in the crystal-clear waters of the North Andaman Sea. | Denis Cadon

Day 7 & 8 – Richelieu Rock

Six dives at Richelieu Rock brought a grand finale to the trip, combining dense fish life with outstanding macro diversity.
​Nudibranchs were everywhere: Spotted hypselodoris, ornate sapsucking slug, Chromodoris geometrica, Chromodoris rufomarginata, Chromodoris annulata, Chromodoris reticulata, Risbecia pulchella, Glossodoris atromarginata, Halgerda tesselata mating, Cadlinella ornatissima, bicolor flabellina and ridged Dermatobranchus.
A bright yellow and black patterned Reticulidia suzanneae nudibranch crawling on a textured reef wall in Thailand.
Intricate patterns: The bold, geometric design of the Reticulidia suzanneae nudibranch is a stunning sight on the reefs of Similan National Park. | Denis Cadon
A pair of Doriprismatica atromarginata nudibranchs with ruffled black and white borders resting next to a white egg ribbon on a reef.
The cycle of life: A Doriprismatica atromarginata nudibranch beside its delicate egg mass, captured in the rich waters of the North Andaman Sea. | Denis Cadon
A vibrant Tiger Egg Cowrie (Cuspivolva tigris) with bold orange and black stripes nestled among the branches of a pink soft coral in Thailand.
Hidden gems: The brilliant stripes of a Tiger Egg Cowrie create a stunning visual contrast against the delicate textures of the North Andaman reefs. | Denis Cadon
Two ornate ghostpipefish hovered delicately in the current, while a thorny seahorse remained anchored to the reef. Harlequin shrimps added flashes of colour, and a juvenile yellow boxfish drifted nearby.
A yellow Ornate Ghost Pipefish (Solenostomus paradoxus) camouflaged against a colorful reef wall in the Similan Islands.
Masters of disguise: The intricate details of an Ornate Ghost Pipefish make it one of the most sought-after sightings for divers in Similan National Park.
A pair of Harlequin Shrimp (Hymenocera picta) with their distinctive blue and pink spots tucked into a rocky crevice on a Thailand reef.
Vibrant reef residents: A beautiful pair of Harlequin Shrimp, known for their striking patterns and unique diet, found during a dive in the North Andaman Sea.
A large, dark Giant Moray Eel resting its head near a vibrant coral outcrop featuring pink and orange sponges.
Reef sentinels: A massive Moray Eel peers out from a colorful coral head in the pristine waters of Similan National Park. | Denis Cadon
In the blue, the full “gang” was present: bluefin trevallies, giant trevallies, rainbow runners, amber jacks and longnose emperors hunting continuously. They even teamed up with a giant moray eel near the bottom of the pinnacle for a hunt on our last dive. Schools of barracudas circled the pinnacle, while longfin batfish hovered elegantly in mid-water.
A group of large Emperor fish, including a Longnose Emperor, swimming through dark, shaded reef areas in the Similan Islands.
"The Gang": A group of formidable Longnose Emperors patrol the deep recesses of the reef in Similan National Park. | Denis Cadon
Four White Eyed Moray Eels (Gymnothorax thyrsoideus) sharing a single rocky crevice on a vibrant reef in Thailand.
Crowded quarters: A group of White Eyed Moray Eels peeking out from their rocky home in Similan National Park. | Denis Cadon
A Zebra Moray Eel (Gymnomuraena zebra) displaying its distinctive dark and light striped pattern as it emerges from a reef.
Striking patterns: The unique, banded appearance of a Zebra Moray Eel captured in the rich waters of the North Andaman Sea. | Denis Cadon
Moray eels were well represented with zebra morays and white-eye morays moving between crevices, completing a site that once again delivered both scale and detail in perfect balance.
A scuba diver, Dive Guide Julien, swimming through a massive, swirling bait ball of small silver fish in the deep blue waters of the Andaman Sea.
Surrounded by life: Dive Guide Julien is engulfed by a spectacular swirling bait ball, a common and breathtaking sight in the vibrant waters of the Similan Islands. | Denis Cadon
A bright orange Tomato Anemonefish (Amphiprion frenatus) with a signature black spot swimming beside its host anemone.
Bold and beautiful: The striking orange and black of a Tomato Anemonefish stands out among the swaying tentacles of a healthy reef in the Similan Islands. | Denis Cadon
A colorful Peacock Mantis Shrimp (Odontodactylus scyllarus) peering out from its sandy burrow under a reef ledge.
Master of the reef: Known for its incredible eyes and powerful punch, the Peacock Mantis Shrimp is a colorful wonder of the North Andaman Sea. | Denis Cadon
The final evening brought everyone together on the upper deck for our traditional BBQ, a well-earned moment after days of diving. The air was warm, the sea calm, and the boat gently rocking under a sky full of stars. Between grilled food, shared stories and laughter, the atmosphere slowly shifted from relaxed to festive, and before long, the music took over and the deck turned into a dance floor. A perfect way to close the trip — somewhere between celebration and that quiet feeling of not quite wanting it to end.

Day 8 - Return to Ranong

After these final dives, we made our way back toward Ranong, closing another North Andaman expedition filled with contrasts — from fast-paced pelagic encounters to intricate macro discoveries — exactly the kind of balance that makes this region so unique.
​Some trips are measured in sightings. Others in the rhythm they leave behind.
This one offered both — from powerful encounters in the blue to the smallest details hidden in the reef.
Until the next tide brings us together again — see you soon, fellow divers.
Four scuba divers—Dive Guide Julien, Dive Guide Joy, Denis, and Pascal—posing in full gear on the deck of a dive boat at sunset.
The dream team: Ending an incredible journey in the Andaman Sea with Dive Guides Julien and Joy, alongside Denis and Pascal.
A close-up underwater selfie of Pascal and Denis wearing scuba masks and regulators during a dive.
Deep blue memories: Pascal and Denis sharing one last look at the stunning reefs of Similan National Park.
Photos Taken by Denis Cadon
]]><![CDATA[Trip report | Thailand | South & North Andaman Expedition, 29th March – 5th April 2026]]>Wed, 15 Apr 2026 06:27:39 GMThttps://www.thesmilingseahorse.com/blog/trip-report-thailand-south-north-andaman-expedition-29th-march-5th-april-2026
A wide sunset view over the calm Andaman Sea with rocky islands on the horizon, featuring a
This expedition through the Andaman Sea unfolded as a gradual exploration of both landscapes and marine life, shaped by shifting currents, encounters, and the quiet surprises hidden along the reefs. While we don't have photos for every sightings, we had some really special encounters!!! The highlight was probably a snaggletooth shark and Bowmouth guitarfish two very rare of the many sharks and rays seen this week!!! 
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From the dramatic limestone formations of the South Andaman to the exposed pinnacles of the North, each dive revealed a new layer of biodiversity. From the sheltered bays of Koh Phi Phi and Koh Lanta to the dynamic sites of the Similan and Surin National Parks, the week developed into a seamless blend of colourful reefs, schooling fish, and intricate macro life.

Day 1 – From Phuket to Koh Phi Phi National Park

We departed this adventure from Phuket with our guests from France, the UK and the USA, setting course toward the iconic Phi Phi Islands. Known for their towering limestone cliffs and emerald waters, the islands also shelter vibrant reefs teeming with life.
Anchored beneath the cliffs for the night, the atmosphere was calm and promising — a quiet beginning before the rhythm of diving took over.
Several Moorish Idols swimming in front of a massive, swirling silver bait ball in the deep blue Andaman Sea.
Contrast in the blue: Elegant Moorish Idols drift past a colossal bait ball, showcasing the immense scale of marine life in the Similan Islands.
A dramatic sunset over the ocean with orange and pink crepuscular rays fanning out across a darkening sky near rocky islets.
Nature’s light show: Stunning crepuscular rays paint the sky over the North Andaman Sea, marking the end of another spectacular day of diving.

Day 2 – Koh Phi Phi & Koh Lanta National Park

Our check dive at Bida Nok immediately set the tone. Hypselodoris purpureomaculosa added colour to the reef alongside ghostpipefish and flounders resting on the sand. A hawksbill turtle cruised by while a group of ten blacktip reef sharks patrolled the shallows. A tigertail seahorse clung delicately to the reef, while purple urchin shrimps moved among spines.
Around them, schools of five-lined snappers, yellowback fusiliers and Moorish idols filled the water column, joined by butterflyfish, surgeonfish and parrotfish grazing the reef.
Macro life was already hinting at what was to come — a richness that would only intensify as the expedition progressed.
A Blacktip Reef Shark (Carcharhinus melanopterus) swimming over a rocky reef accompanied by a small school of yellow snappers in the Andaman Sea.
Grace in the shallows: A Blacktip Reef Shark glides effortlessly past a school of snappers, captured in the pristine waters of the Similan Islands. | Renaud Liberge
A close-up view of a Hawksbill Turtle (Eretmochelys imbricata) swimming gracefully over a colorful coral reef in Thailand.
A gentle encounter: A beautiful Hawksbill Turtle navigates the vibrant coral gardens of the North Andaman Sea. | Frederique Bechet
Moving on to Koh Lanta national park, we started with a macro treasure hunt at Koh Haa Cathedral. Noumea norba, Bornella, Phyllidiopsis striata, Halgerda bacalusia (candy halgerda) and Halgerda willeyi decorated the walls, while an Anker whip coral shrimp carrying eggs hovered delicately. Coral groupers, copperband butterflyfish, Indian sailfin tang and cleaner wrasse completed the scene.
A bright orange Vermilion Grouper resting among white and pink soft corals with a school of small reef fish in the blue Andaman Sea.
A splash of color: A Vermilion Grouper finds shelter in a garden of soft corals, a testament to the thriving marine life of the Similan Islands.
A macro close-up of a mosaic-patterned Bornella anguilla nudibranch with orange-tipped rhinophores crawling on a bright yellow sponge.
Mosaic of the reef: The incredible detail and vivid colors of a Bornella anguilla nudibranch captured against a luminous yellow background.
At Hin Daeng & Hin Muang, the pace picked up with schools of rainbow runners, giant trevallies and bluefin trevallies hunting in the blue. Batfish hovered mid-water, a hawksbill turtle passed by, and ghostpipefish blended into the reef. Jellyfish drifted through the current while juvenile emperor angelfish, bentstick pipefish, juvenile brown coral blenny, peacock mantis shrimp and longnose hawkfish kept divers scanning every corner.
Schools of fusiliers, snappers and surgeonfish added constant movement.
A group of Longfin Batfish (Platax teira) swimming through cathedral-like sunbeams in the clear blue waters of the Andaman Sea.
Underwater cathedral: Longfin Batfish glide through spectacular light rays, a serene moment captured during our deep blue exploration.
A school of predatory Trevally fish diving into a massive, dense bait ball of smaller fish in the open ocean.
The hunt is on: Predatory Trevally strike with lightning speed, scattering a massive bait ball in a display of raw reef energy.
The night dive at Hin Daeng revealed Noumea sp., Hypselodoris sp., swollen bubble snails, barred-fin moray and minor moray, along with blacktail Zanzibar urchin shrimp, skeleton shrimp, tapestry shrimp and spotted reef crabs. Around them, sleeping parrotfish, hunting lionfish and active shrimps completed the nocturnal reef.
A tranquil sunset over the Andaman Sea with dark rocky formations in the foreground, marking the start of Day 3 in Koh Tarutao National Park.
Golden hour at Koh Tarutao: The sun sets over the calm horizon as our expedition moves into the southern reaches of the Andaman Sea.

Day 3 – Koh Tarutao National Park

At 8 Mile, visibility opened wide over the pinnacle. Bentstick pipefish hovered above the reef while redbar anthias  and juvenile angelfish filled the water column. Fimbriated morays peered from crevices as Spanish mackerel and great barracuda cruised past. The unusual half grouper–half barramundi added a curious highlight (same one as last trip).
Schools of fusiliers, surgeonfish and snappers moved constantly in the current.
A vibrant juvenile Emperor Angelfish with concentric electric blue and white circular patterns swimming near a sea urchin.
Nature’s geometry: The mesmerizing circular patterns of a juvenile Emperor Angelfish stand out against the backdrop of a rocky reef.
A large, mottled Giant Grouper with its mouth open while a small cleaner wrasse performs its duties on a colorful reef.
Spa day on the reef: A strange looking Giant Grouper pauses at a cleaning station, allowing cleaner wrasse to attend to it in Koh Tarutao National Park. | Frederique Bechet
Stonehenge brought a quieter atmosphere with a seahorse, Phestilla melanobrachia and flounders resting on the sand, surrounded by wrasses, damsels and butterflyfish moving between soft corals.

​At Koh Taru, schools of five-lined snappers dominated the reef, joined by Phestilla melanobrachia and tiger cowries. Fusiliers, goatfish and sweetlips added movement as the light softened toward sunset.
Two pink Skunk Anemonefish (Amphiprion akallopisos) hovering above their host anemone with a large, intricate sea fan in the background.
A perfect partnership: Skunk Anemonefish find safety among the tentacles of their host, framed by the delicate beauty of a giant sea fan.
A vibrant yellow Tigertail Seahorse (Hippocampus comes) with dark markings gripping a branch of pink soft coral.
Master of disguise: A bright yellow Tigertail Seahorse anchors itself to a colorful reef, showing off the incredible camouflage found in Koh Tarutao National Park.

Day 4 – Koh Lanta National Park

Hin Daeng & Hin Muang once again delivered strong currents and active reefs, with schools of trevallies, fusiliers and snappers swirling around the pinnacles, alongside batfish, ghost pipefish, surgeonfish and reef predators patrolling the blue.
A pair of Redtail Butterflyfish (Chaetodon collare) swimming in front of a large, complex orange sea fan on a healthy reef.
Elegant residents: A duo of Redtail Butterflyfish navigates the intricate branches of a massive sea fan in the southern Andaman Sea.
A highly camouflaged Ghost Pipefish (Solenostomus paradoxus) hovering vertically near a sea fan on a vibrant reef wall.
Hidden in plain sight: The remarkable camouflage of an Ghost Pipefish allows it to blend perfectly into the surrounding reef life.
At Koh Haa Chimney, the dive shifted back to macro life with Halgerda bacalusia, Cuthona sibogae, Risbecia pulchella and ghostpipefish. Inside the structure, glassfish shimmered while outside, sweetlips, groupers, parrotfish and angelfish filled the reef.
After the dive, we began our overnight crossing toward the Similan Islands, leaving the southern reefs behind.
A close-up of a Risbecia pulchella nudibranch, featuring a creamy body with yellow spots and a distinct purple ruffled border.
Elegant patterns: The striking purple edge and delicate spots of a Risbecia pulchella nudibranch found during Day 5 of our expedition in Similan National Park.
A macro image of a Halgerda bacalusia nudibranch, featuring a white body with a network of orange-yellow ridges and dark-tipped gills.
Geometry in the blue: The striking ridges of a Halgerda bacalusia captured against the reef. | Renaud Liberge

Day 5 – Similan National Park

West of Eden surprised us with a rare snaggletooth shark, alongside whitetip reef sharks cruising the reef. Pygmy pipehorse hovered delicately while McCosker’s flasher wrasse darted through the water column. The reef revealed a batwing psychedelic seaslug and a perfectly camouflaged devil scorpionfish, surrounded by butterflyfish, surgeonfish, wrasses and schools of fusiliers.
A colorful male McCosker's flasher wrasse (Paracheilinus mccoskeri) displaying vibrant blue, orange, and red colors while swimming among smaller reef fish in the deep blue.
Lighting up the reef: A stunning McCosker's flasher wrasse in full display, a highlight of our dives at Elephant Head Rock.
A macro close-up of a Batwing psychedelic seaslug (Sagaminopteron psychedelicum) featuring intricate patterns of purple, orange, and green on a soft coral background.
Underwater art: The mind-bending colors and patterns of a Batwing psychedelic seaslug, one of the most unique macro discoveries in the Similan Islands.
At Elephant Head Rock, blue ribbon eels waved from their burrows while octopus moved across the rocks. Three-spot angelfish and a young adult yellow boxfish stood out, while an Andaman jawfish guarded its eggs. Trevallies, snappers and sweetlips completed the dramatic setting.
North Point brought whitetip sharks, a Jenkins whipray and a juvenile Spanish dancer, alongside a wavy sap-sucking seaslug and a passing guitar shark. Schools of fusiliers and snappers added movement.
Two vibrant male Blue Ribbon Eels (Rhinomuraena quaesita) extending from the same burrow with mouths open against a rocky reef background.
Double the wonder: A rare sighting of two Blue Ribbon Eels sharing a single burrow at Elephant Head Rock.
A large Jenkins' Whipray (Pateobatis jenkinsii) resting on the sandy seafloor near a rocky outcrop in the clear waters of the Similan Islands.
Resting giant: A Jenkins' Whipray camouflaged against the sand, a common but always impressive resident of the North Andaman reefs.
At Koh Bon Ridge during sunset, a whitetip reef shark moved repeatedly in and out of the reef, patrolling close to divers in a memorable encounter.
The blackwater dive revealed spear mantis shrimp larvae, squids, pelagic snails, zoea crabs, siphonophores, “pompom tail” shrimp larvae, flatworm larvae, blenny larvae, shrimp larvae, moray eel larvae and larval anemones drifting through the dark.

Blackwater once again delivered the surreal, reminding us that some of the ocean’s most fascinating life exists far from the reef.

From the mesmerizing patterns of macro life to the "alien" encounters of the midnight vertical migration, these seven images capture the incredible biodiversity found across our expedition through the Similan and Koh Tarutao National Parks.

Day 6 – Similan National Park
​

At Koh Bon Bay, orange-spotted glassy bubbles (Hyppo snails)  on the reef while a school of batfish gathered in the current alongside giant trevallies and double-spotted queenfish.
A Bowmouth Guitarfish (Rhina ancylostoma) swimming over a rocky reef accompanied by a diverse school of tropical fish in clear blue water.
A prehistoric silhouette: The rare Bowmouth Guitarfish, also known as a Mudray, glides over the reef during an expedition to the Burma Banks.
A large, shimmering school of silver Longfin Batfish (Platax teira) gathered around a coral pinnacle in the Similan Islands.
Silver symphony: A dense school of Longfin Batfish creates a spectacular wall of silver at the Koh Bon pinnacle.
On Koh Bon West Ridge, an incredible encounter with a bowmouth guitar shark, alongside Spanish dancer eggs, dogtooth tuna and Spanish mackerel hunting in the blue, while fusiliers and surgeonfish filled the reef.
A silhouette of a scuba diver hovering in clear blue water above a large sea anemone hosting a bright orange clownfish.
Exploring the blue: A diver observes the perfect symbiosis between a clownfish and its anemone host in the Andaman Sea.
A large, colorful Titan Triggerfish (Balistoides viridescens) swimming over a hard coral reef under bright, sunny surface conditions.
Reef guardian: A Titan Triggerfish cruises over the coral gardens, showcasing the vibrant marine life found in Thailand's national parks.
Koh Bon Pinnacle was alive with schools of batfish, clown triggerfish, bluefin trevallies, barracudas and yellowback fusiliers.
At Koh Tachai Pinnacle, large schools of barracudas, batfish, giant trevallies, bluefin trevallies and bigeye trevallies dominated the dive, joined by marble groupers and painted spiny lobsters hiding in the rocks.
A large, bright pink soft coral (Dendronephthya) blossoming on a rocky reef, surrounded by small tropical fish in clear blue water.
A burst of color: This magnificent pink soft coral is a testament to the healthy, nutrient-rich currents that flow through the Similan Islands.
A dense, swirling school of chevron barracuda swimming in the open blue water near the ocean surface.
Power in numbers: A massive school of barracuda creates a shimmering silver wall, a thrilling sight for any diver in the Andaman Sea.
The night dive at Koh Tachai Reef brought hunting behaviour, with schools of checkered snappers and barracudas using our lights to hunt, while giant moray eels swam freely and blacktip sharks cruised the reef.
A Blacktip Reef Shark (Carcharhinus melanopterus) swimming swiftly over a dark reef at night, with its distinctive black-tipped dorsal fin visible against the dark water.
Midnight patrol: A Blacktip Reef Shark cruises the reef edge under the cover of darkness, a prime example of the apex predators encountered during our night dives.
A side-profile view of a Blacktip Reef Shark swimming over rocky coral terrain at night, illuminated by a dive light.
Into the shadows: The sleek silhouette of a Blacktip Reef Shark emerges from the darkness, showcasing the thrilling wildlife sightings possible in the Andaman Sea after sunset.

Day 7 – Surin National Park (Richelieu Rock)
​

Four dives at Richelieu Rock delivered a spectacular finale. White and yellow ornate ghostpipefish hovered delicately while peacock mantis shrimp and tigertail seahorses added macro highlights.
A macro shot of a spiny Ghost Pipefish (Solenostomus paradoxus) hovering near vibrant pink soft corals.
Master of disguise: A Ghost Pipefish blends perfectly with the surrounding soft corals in the Similan Islands.
A close-up of a bright yellow Tigertail Seahorse (Hippocampus comes) anchored to the reef substrate.
Golden discovery: A stunning Tigertail Seahorse found tucked away in the rocky crevices of the North Andaman reefs.
Schools of amber jacks, bigeye jacks, longnose emperors, giant trevallies, bluefin trevallies and rainbow runners filled the blue, while juvenile bridled monocle bream, baby octopus, Spanish mackerel and juvenile clown triggerfish added variety. Female Moyer’s dragonet and male Morison’s dragonet completed the scene.
A large, swirling bait ball of small silver fish being pursued by several large red snappers in clear blue water.
Eye of the storm: Large snappers dive through a massive bait ball, a spectacular display of predatory action in the Andaman Sea.
A dynamic underwater scene featuring schools of trevally and barracuda silhouetted against the bright surface sun over a coral reef.
The morning rush: Schools of trevally and barracuda congregate at the reef's edge as the sun breaks through the surface.
Nudibranch diversity was exceptional, including Risbecia pulchella, Chromodoris geometrica, Glossodoris atromarginata, Hypselodoris bullocki, bicolor flabellina, Gymnodoris nigricolor and Glossodoris pallida, while flatworms such as Pseudobiceros sp7 added even more colour.
Around them, dense schools of fusiliers, snappers and glassfish wrapped the pinnacle in constant motion.
A massive, dense school of silver Jacks (Caranx) swirling in clear blue water over a dark reef edge.
Tornado of silver: A spectacular school of Jacks creates a living vortex in the nutrient-rich waters of the Andaman Sea.
A diverse school of reef fish, including snappers and emperors, swimming over a lush garden of pink soft corals.
The crown jewel: Intense marine biodiversity flourishes over the iconic pink soft corals of Richelieu Rock.

Day 8 – Similan National Park & Khao Lak Coast
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Our final dives brought us back to Koh Tachai Pinnacle, where a hawksbill turtle, schools of batfish, bigeye jacks, barracudas and Spanish mackerel closed the trip with strong pelagic action.
A pair of vibrant yellow and black Raccoon Butterflyfish (Chaetodon lunula) swimming past a large, intricate red gorgonian sea fan on a steep reef wall.
Sunset colors: A pair of Raccoon Butterflyfish, known for their distinct mask-like markings, glide past a massive sea fan in the North Andaman Sea.
A dense, circular school of Bigeye Trevally silhouetted against the bright surface sun in deep blue water.
Oceanic vortex: A massive school of Bigeye Trevally creates a shimmering silhouette against the midday sun.
A Kuhl's Stingray (Neotrygon kuhlii), also known as a Bluespotted Maskray, resting on the sandy seafloor near soft corals in clear daylight.
Master of the sand: A Kuhl’s Stingray—easily identified by its kite-like shape and blue spotting—rests on the seafloor during a daytime exploration of the reef.
At Boonsung Wreck, a completely different atmosphere awaited. Blue-spotted Kuhl’s rays rested on the sand, honeycomb morays hid within the structure and bentstick pipefish hovered nearby. Schools of fusiliers, snappers, sweetlips and trevallies turned the wreck into a true fish haven.
A large school of longfin bannerfish (Heniochus acuminatus) swimming together against a dark reef slope in deep blue water.
Graceful gliders: A school of bannerfish maneuvers along the reef, their long white dorsal filaments trailing behind them like ribbons in the current.
A vibrant macro shot of a Honeycomb Moray Eel (Gymnothorax favagineus) with its mouth slightly open, tucked into a colorful coral crevice surrounded by small orange fish.
Pattern perfection: The striking leopard-like markings of a Honeycomb Moray Eel emerge from a vibrant reef corner, a favorite find for underwater photographers.
We then returned to Tap Lamu Pier in Khao Lak, saying goodbye after another rich and diverse journey through the Andaman Sea.
From limestone reefs to offshore pinnacles, this journey captured the changing rhythm of the Andaman Sea — where each dive revealed a new balance between movement, colour and hidden detail.
Until the next tide brings us together again — dive well, dive aware, and see you soon, fellow divers.
A vibrant orange sun setting over the calm ocean and distant islands, viewed from the deck of a dive boat.
Golden hour at sea: The sun dips below the horizon, painting the sky in hues of pink and orange—the perfect end to another day of exploration in Thailand's national parks.

Photos by: Franck Fogarolo, Frederique Bechet and Renaud Liberge

]]><![CDATA[Trip report | Marine Biology cruise with Whale Shark specialist | 20th - 27th March 2026]]>Tue, 31 Mar 2026 02:47:07 GMThttps://www.thesmilingseahorse.com/blog/trip-report-andaman-whale-shark-research-expedition-20th-27th-march-2026
An aerial drone view of a lush limestone island in Thailand with a secluded turquoise lagoon, featuring a dive boat anchored in the crystal-clear water.
: A smiling scuba diver, Rinda
Meet the expert: Rinda "Mony," the "Whaleshark Guru" from the Thailand Whale Shark Project, who joined our March 2026 cruise to share her deep knowledge of these majestic ocean giants.
A wide shot of a vibrant orange sun setting over the dark blue horizon of the Andaman Sea, with soft purple and gold clouds above.
Golden horizon: A breathtaking sunset at sea provides a moment of reflection between our underwater adventures in Thailand's national parks.

Some expeditions are defined by what you see. Others by what you come to understand.
​

We departed from Ranong, welcoming our international group of guests from Italy, France, the UK and the US, and set course for a Marine biology expedition with a Whale Shark Specialist, Mony to learn more about the biggest fish in the seas!

While the ocean chose not to reveal them this time, the experience took on a different depth. Throughout the week, Rinda, also known as Mony, from the Thailand Whale shark project, delivered daily presentations exploring whale shark biology, behaviour, and conservation challenges in Thailand.
​
These sessions brought a meaningful layer to the expedition, connecting each dive to a broader ecological perspective — linking what we observed underwater to the larger story of marine life in the Andaman Sea. From North to South Andaman, the journey unfolded as a rich exploration of pelagic encounters, vibrant reefs, and intricate macro life — shaped as much by discovery as by understanding.

​Day 2 – Surin National Park & Richelieu Rock

​Our check dive in the Surin Islands at Koh Chi offered a gentle but vibrant start. Garden eels swayed over sandy patches while Halgerda tesselata, blue dragon and scorpionfish blended into the reef. Coral groupers hovered near bommies alongside Clark’s anemonefish and false anemonefish, while schools of yellowback fusiliers and neon fusiliers moved through the water column. Around them, Moorish idols, copperband butterflyfish, blue-barred parrotfish and bullethead parrotfish completed the reef scene.
Macro life was already hinting at what was to come — a richness that would only intensify as the expedition progressed.
A school of Raccoon Butterflyfish (Chaetodon lunula) showcasing their distinctive yellow and black mask patterns.
A striking group of Copperband Butterflyfish navigates the coral reef with precision. | Frederique Bechet
A white Halgerda Bacalusia nudibranch with orange ridges crawling over a bright red sponge.
The intricate orange-and-white patterns of this Halgerda Bacalusia nudibranch stand out against a vivid red sponge. | Renaud Liberge
A dense school of predatory fish at Richelieu Rock, often referred to as
Predatory patrol: Massive schools of fish congregate at Richelieu Rock, creating one of the most dynamic underwater scenes in the world.
Two Moorish Idols (Zanclus cornutus) swimming through a dramatic rock archway, silhouetted against the bright surface sun.
Into the light: Moorish Idols navigate the dramatic topography and sunbeams of the Surin Islands' reef systems.
At Richelieu Rock, visibility was excellent and the site delivered immediately. The gang — giant trevallies, bluefin trevallies, bigeye trevallies, longnose emperors and rainbow runners — hunted through dense clouds of glassfish. Barracudas patrolled the edges while batfish hovered calmly mid-water.

​Closer to the reef, harlequin shrimps, thorny seahorse, cleaner pipefish and orange-spotted pipefish added intricate detail. Tomato anemonefish, white-eye moray eels, giant moray eels and zebra moray eels occupied every crack, while octopus shifted colours between rocks. Headshield slugs, reticulated sapsucking slugs, ornate sapsucking slugs and Moyer’s dragonet were all present, alongside schools of five-lined snappers, twinstripe fusiliers and lunar fusiliers.
A vibrant yellow Tigertail Seahorse (Hippocampus comes) using its prehensile tail to anchor itself to a branch of colorful soft coral.
A bright yellow Tigertail Seahorse clings perfectly to the vibrant soft corals of the reef. | Renaud Liberge
A close-up profile of a Giant Moray Eel (Gymnothorax javanicus) resting among coral rubble, showcasing its speckled skin and powerful jaw.
A massive Giant Moray Eel peeks out from its rocky crevice, showing off its impressive size and patterned skin. | Frederique Bechet
​The night dive revealed blunt decorated spider crabs, orange-spotted pipefish, boxer banded shrimps, Durban dancing shrimps, cleaner shrimps and pencil sea urchins. Ridged egg cowries and sixline soapfish appeared, while sleeping parrotfish, triggerfish locked into the reef and hunting moray eels completed the nocturnal scene.

​Day 3 – Similan National Park, Koh Tachai & Koh Bon

​Koh Tachai delivered strong currents and action-packed dives. Blacktip reef sharks cruised the reef, a hawksbill turtle passed by, and large schools of barracudas, dogtooth tuna and Spanish mackerel moved through the blue. African pompano, adult black and white snappers, lobsters and glassfish filled every level of the dive.
A Hawksbill sea turtle (Eretmochelys imbricata) swims gracefully over a rocky reef slope in clear blue water.
A beautiful Hawksbill turtle glides effortlessly over the rugged reef terrain. | Frederique Bechet
A dense cloud of translucent glassfish hovering above a vibrant field of pink and purple soft corals on a healthy reef.
Thousands of tiny glassfish form a shimmering cloud over a garden of vibrant soft corals.
A massive, swirling vortex of chevron barracuda schooling in the open ocean with sunbeams piercing through the water.
A shimmering silver tornado of barracuda creates a mesmerizing spectacle in the deep blue. | The Smiling Seahorse
A sleek Blacktip reef shark (Carcharhinus melanopterus) patrols a shallow reef plateau alongside a small school of yellow snappers.
A powerful Blacktip reef shark cruises past a colorful school of snappers along the reef edge. | Renaud Liberge
During the navigation to Koh Bon, dolphins came to greet the boat, riding the bow wave and adding a rare surface interval moment that stayed with everyone on board.

At Koh Bon Pinnacle, one group encountered a large shark in the deep, most likely a bull shark, while the pinnacle itself pulsed with schools of yellowback fusiliers and neon fusiliers. Coral groupers, peacock groupers, powder-blue surgeonfish and Indian sailfin tang added structure and colour to the reef.
​
On the North Ridge and West Ridge, reef life remained dense and dynamic, with anemone crabs, dogtooth tuna, rainbow runners and mackerels hunting through thick schools of glassfish, while wrasses, blennies and damsels filled every available space.
A Porcelain Anemone Crab (Neopetrolisthes maculatus) with its distinctive spotted pattern peeking out from the stinging tentacles of its host anemone.
A tiny Porcelain Anemone Crab finds safety and shelter among the protective tentacles of its host. | Frederique Bechet
A large school of yellowback fusiliers (Caesio teres) swimming in unison through the bright blue waters of a healthy coral reef.
A vibrant school of fusiliers creates a flash of yellow and silver as they sweep across the reef. | The Smiling Seahorse
​The blackwater dive introduced squids, salps sheltering small fish and pyrosomes drifting through the dark.
A translucent squid with shimmering iridescent spots and large eyes suspended against the pitch-black background of the open ocean at night.
A translucent squid glows with iridescent light while navigating the deep blackwater during its nightly migration.
A tiny, larval juvenile fish with a transparent body and reflective metallic scales captured during a blackwater dive.
A fragile juvenile fish drifts through the dark, showcasing the incredible transparency common to larval marine life.
A glowing, cylindrical pyrosome colony floating in the dark, providing a safe shelter for a tiny juvenile fish nestled inside its opening.
A glowing pyrosome acts as a natural sanctuary for a tiny juvenile fish seeking protection in the vast open sea.
A silvery juvenile fish swimming alongside a large clump of organic detritus, known as marine snow, against the dark void of the ocean at night.
A tiny juvenile fish drifts through the darkness alongside nutrient-rich marine snow during its nightly journey.
A small, iridescent squid with shimmering colorful spots on its mantle navigating through the pitch-black water.
Shimmering in the dark, a small squid displays a brilliant array of iridescent colors while moving through the blackwater.
A front-facing macro shot of a juvenile fish with large, reflective eyes and translucent fins suspended in the blackwater.
Caught in the light, a juvenile fish reveals its delicate, translucent features and large reflective eyes.

​Day 4 – Similan Islands & Crossing

​At North Point, a Napoleon wrasse cruised past while squat shrimps, mantis shrimps and Durban dancing shrimps animated the reef. Anemone crabs, Clark’s anemonefish, moray eels and topsail drummers were joined by blueface angelfish, regal angelfish, butterflyfish and schools of fusiliers.
A Giant Moray Eel (Gymnothorax javanicus) shares a rocky crevice with several bright red Pinecone Soldierfish.
A Giant Moray Eel rests within a sheltered reef alcove alongside a group of vibrant Pinecone Soldierfish. | Renaud Liberge
A Spearing Mantis Shrimp (Lysiosquillina lisa) peering out from its circular burrow in the substrate, showcasing its large, complex eyes.
A formidable Spearing Mantis Shrimp keeps a watchful eye from the safety of its deep, sand-lined burrow. | Renaud Liberge
​We then stopped at Island #8, also known as Donald Duck Bay, where white sand and granite boulders offered a striking contrast to the dives and a magnificent view from Sailrock offering sight on the blue and transparent water of the Similans.
A juvenile Blackspotted Boxfish (Ostracion meleagris) with its distinctive cuboid body and yellow-and-black spotted pattern swimming over a coral reef.
A juvenile blackspotted boxfish displays its striking geometric patterns while navigating the reef formations.
A tiny Squat Shrimp (Thor amboinensis), also known as a Sexy Shrimp, perched on the reef with its tail arched upward.
The charismatic squat shrimp, famously known as the "sexy shrimp," adds a splash of personality to the macro landscape.
A vibrant male Blue Ribbon Eel (Rhinomuraena quaesita) with its bright blue body and yellow dorsal fin extending from a burrow in the sandy reef floor.
A bright blue ribbon eel peeks out from its burrow, showcasing the dramatic colors found at Elephant Head Rock. | Renaud Liberge
​Elephant Head Rock delivered dramatic topography with blue ribbon eels, adult yellow boxfish, juvenile blackspotted boxfish, red anthias, surgeonfish, blue dragon and giant trevallies weaving through the formations.
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At West of Eden, two pipehorse fish hovered delicately while spearing mantis shrimps, squat shrimps, “sexy shrimps”, hawksbill turtle, blue dragon and a psychedelic batwing slug created a richly layered dive. Topsail drummers, fusiliers, snappers, angelfish, wrasses and parrotfish completed the reef.
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We then crossed overnight toward Koh Lanta, leaving the granite islands behind.

​Day 5 – Hin Daeng & Hin Mueang

​Hin Mueang was full of life, with glassfish and juvenile fusiliers forming dense schools constantly targeted by hunting trevallies, African pompano and rainbow runners. Juvenile emperor angelfish, ghostpipefish, Bornella anguilla, Halgerda tesselata and phyllidia of various colours covered the reef.
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Banded boxer shrimps, Durban dancing shrimps and cleaner shrimps filled every crevice, while titan triggerfish dug into the reef and redtooth triggerfish hovered above. Topsail drummers completed the scene.
A juvenile Emperor Angelfish (Pomacanthus imperator) with its striking pattern of concentric blue, white, and black circles swimming against a backdrop of pink soft corals.
A young Emperor Angelfish displays its hypnotic swirling patterns while navigating a garden of soft corals. | Renaud Liberge
Multiple Bornella Anguilla nudibranchs with their intricate, branching cerata crawling over red algae and reef substrate.
These fascinating Bornella Anguilla nudibranchs blend into the reef as they search for food among the red algae. | Renaud Liberge
A large Titan Triggerfish (Balistoides viridescens) with its characteristic scales and powerful jaw swimming near a bright orange sea fan
: The imposing Titan Triggerfish patrols the reef edge near a vibrant orange gorgonian sea fan.
A red and white Ghost Pipefish (Solenostomus paradoxus) hovering near an orange sponge, perfectly mimicking its surroundings.
A master of disguise, this Ghost Pipefish hides in plain sight against the colorful reef backdrop. | Renaud Liberge
​Hin Daeng delivered ghostpipefish, Glossodoris cincta and its eggs, ornate elysia, giant moray eels hunting in the shallows, Clark’s anemonefish, anemone crabs and tiger egg cowries. Batfish, fusiliers, snappers, surgeonfish, sweetlips and reef fish filled the water column.
A Glossodoris Cincta nudibranch crawling over a reef, displaying its mottled brown body and distinctive multi-colored frilled edge.
A Glossodoris Cincta nudibranch displays its beautifully ruffled and colorful mantle edge while exploring the reef. | Frederique Bechet
A tiny yellow and black striped Tiger Egg Cowrie perched on a branch of pale pink soft coral.
A vibrant Tiger Egg Cowrie stands out against the delicate branches of a soft coral host. | Frederique Bechet
​The night dive intensified the atmosphere with multiple giant moray eels hunting, small octopus camouflaging along the wall, and a constant movement of crabs and shrimps across the reef.

​Day 6 – Koh Tarutao National Park

​At 8 Mile, excellent visibility revealed a very friendly marble grouper who looked like he was mixed with a barramoundi, great barracuda, schools of scribbled filefish, juvenile emperor angelfish, juvenile blue-ringed angelfish, stonefish, yellowtail barracuda and schools of giant trevallies, alongside fusiliers, snappers, surgeonfish and reef fish.
A large Marbled Grouper (Epinephelus fuscoguttatus) displaying its intricate brown and white mottled pattern while swimming against a deep blue ocean backdrop.
A Marbled Grouper shows off its stunning natural camouflage while patrolling the reef. | Renaud Liberge
A Scribbled Filefish (Aluterus scriptus) with its distinctive elongated body and blue-spotted pattern swimming over a healthy coral reef.
The uniquely patterned Scribbled Filefish glides gracefully above a bustling reef community.
A well-camouflaged Scorpionfish resting on a rocky sea floor surrounded by vibrant purple soft corals.
Blending perfectly into its surroundings, this Scorpionfish waits patiently among the corals for passing prey. | Renaud Liberge
A juvenile Blue Ringed Angelfish (Pomacanthus annularis) featuring brilliant blue and white concentric stripes on its deep blue body.
The electric blue patterns of a juvenile Blue Ringed Angelfish provide a striking pop of color against the reef. | Frederique Beche
​Stonehenge offered three tigertail seahorses, including one black pregnant individual, surrounded by bird wrasse, moon wrasse and sixline wrasse, along with parrotfish, scorpionfish, butterflyfish and damsels.
A Tigertail Seahorse (Hippocampus comes) with a dark mottled pattern clings to a reef structure near vibrant red sea fans.
A master of camouflage, this Tigertail Seahorse blends seamlessly into the reef textures. | Frederique Bechet
Two slender Razorfish (Aeoliscus strigatus) swimming in their characteristic vertical head-down position over a sandy seabed.
A pair of Razorfish navigate the currents in their unique vertical swimming style.
A close-up of a Peacock Flounder (Bothus mancus) showing its blue-ringed patterns and both eyes positioned on the top side of its flat body.
The intricate, flower-like patterns of a Peacock Flounder provide incredible camouflage against the sandy bottom.
​At Steps, the sunset dive featured yellow-scribbled pipefish, Kuhl’s blue-spotted stingray, bamboo shark, flounder and razorfish, alongside fusiliers, goatfish, sweetlips, surgeonfish and reef fish settling into the evening light.

​Day 7 – Koh Lanta National Park

​Hin Mueang again delivered intense action, with schools of dogtooth tuna, Spanish mackerel, rainbow runners and mackerels hunting through glassfish and juvenile fusiliers. Batfish hovered nearby, while two yellow ghostpipefish and topsail drummers added structure.
Hin Daeng revealed yellow and black ghostpipefish and a juvenile hawksbill turtle surfacing for air before resting. Clark’s anemonefish, anemone crabs, ornate sapsucking slugs and reef life filled the dive.

A close-up of a Hawksbill sea turtle (Eretmochelys imbricata) showing its distinctively patterned
​head and shell as it swims over a vibrant coral reef. | Renaud Liberge

A large, craggy limestone karst island rising sharply from a calm, deep blue sea under a clear sky.
The iconic limestone cliffs of Koh Haa tower over the crystal-clear waters of the Andaman Sea. | Renaud Liberge
A large red hermit crab partially emerged from its protective seashell on a sandy and rocky seabed.
A resilient hermit crab carries its portable home across the sandy ocean floor in search of food. | Renaud Liberge
A vibrant underwater scene featuring several purple-based sea anemones surrounded by soft pink corals and dark sea urchins.
A colorful underwater garden thrives with purple anemones and delicate soft corals at the base of the reef.
A sleek, silver dogtooth tuna swimming through the dark, deep blue open water.
A powerful dogtooth tuna patrols the deep blue water near the island's steep drop-offs.
​At Cathedral, massive Glossodoris hikuerensis, Halgerda stricklandi, Halgerda candy, verconia alboannulata (noumea alboannulata), Bornella anguilla, a juvenile hawksbill turtle with a damaged shell, titan triggerfish carrying shells, bannerfish, Moorish idols, giant moray eel, longfin batfish and pinnate batfish created a rich and layered scene.
At the Cheminee, ghostpipefish, Cuthona sibogae, tiger cowrie eggs, giant moray eels, cave fish, sweetlips, snappers, yellowback fusiliers, neon fusiliers, glassfish, ornate elysia, scorpionfish, parrotfish and anemonefish filled the tunnel.

The day ended with our traditional BBQ on board, under calm seas and a sky full of stars.
A macro shot of an Ornate Elysia nudibranch (Elysia ornata) featuring a translucent green body with a distinct black and gold frilled margin, crawling over a textured reef.
The Ornate Elysia nudibranch displays its stunning gold-rimmed parapodia while navigating the diverse reef systems of Koh Phi Phi. | Renaud Liberge
A translucent jellyfish with bright pink internal radial canals and long, flowing tentacles drifting through the dark blue water column.
A ghostly jellyfish pulses through the deep blue, its pink interior glowing against the shadows of the Andaman Sea. | Renaud Liberge
A vibrant Trinchesia sibogae nudibranch with a purple body and numerous pink, yellow-tipped cerata perched on a delicate hydroid branch.
dding a burst of color to the macro world, the Trinchesia sibogae nudibranch shows off its brilliant pink and yellow-tipped cerata. | Frederique Bechet
A bright yellow Tiger Tail Seahorse (Hippocampus comes) with dark banding on its tail, using its prehensile tail to anchor onto a red gorgonian sea fan.
A vivid yellow Tiger Tail Seahorse finds a perfect anchor point among the branches of a colorful gorgonian sea fan. | Renaud Liberge

​Day 8 – Koh Phi Phi & Final Dive

​Bida Nok offered blacktip reef sharks, tigertail seahorse, two ghostpipefish, schools of five-lined snappers, giant moray eels, batfish and schools of fusiliers moving across the reef alongside butterflyfish, surgeonfish and parrotfish.
​At King Cruiser wreck, the sunken ferry now acts as a thriving artificial reef, covered in life. Schools of yellowback fusiliers, bigeye trevallies, school of jacks, snappers circled the structure, while lionfish and groupers, sweetlips and reef fish occupied every level of the wreck.
Closer to the structure, macro life revealed itself in layers: Hypselodoris infucata, Glossodoris atromarginata, Chromodoris aureopurpurea, Hypselodoris sp. 3 and Flabellina rubrolineata decorated the surfaces, turning the wreck into a vibrant underwater mosaic where small details were just as captivating as the schooling fish above.
A vibrant pink Verconia alboannulata nudibranch with a white border and bright orange rhinophores and gills, crawling over a textured, reddish-brown reef.
The striking pink hues of a Verconia alboannulata nudibranch stand out against the rocky substrate, showcasing the intricate detail of macro life. | Frederique Bechet
A detailed 3D illustrated map of the King Cruiser wreck, showing various sections like the wheelhouse, passenger deck, and car deck, with schools of fish depicted around the structure.
A comprehensive map of the King Cruiser wreck highlights key features and depths for divers exploring this massive artificial reef.
We ended the trip in Phuket Marin Charter Pier, saying goodbye after a week rich in encounters, diversity and unforgettable underwater moments.
From open-ocean encounters to the smallest hidden reef life, this journey captured the full spectrum of Andaman diving — shaped by rhythm, diversity, and the quiet magic of life below the surface.
See you soon, fellow divers.

Pictures from Renaud Liberge & Frederique Béchet (pictured below) present on this trip and others from Franck Fogarolo.
A portrait of scuba diver Frederique Bechet smiling warmly on a dive boat at night, wearing a black and purple wetsuit.
Frederique Bechet shares a joyful moment on deck after a successful night dive in the Andaman Sea.
close-up of scuba diver Renaud Liberge geared up in a Mares brand BCD and regulator, with a diving mask on his forehead, prepared for a night dive.
Renaud Liberge prepares to submerge, equipped with professional Mares diving gear for an underwater photography session.
A large, diverse group of smiling people gathered together on the deck of a boat at night, many holding up drinks in a celebratory toast during a group BBQ event.
Divers and crew members come together for the traditional BBQ night group photo, celebrating a week of incredible underwater adventures.
]]><![CDATA[Trip report | 10th - 18th March 2026 | Mergui Archipelago & Burma Banks]]>Fri, 20 Mar 2026 02:53:40 GMThttps://www.thesmilingseahorse.com/blog/trip-report-10th-18th-march-2026-mergui-archipelago-burma-banks
A silhouetted rocky island topped with a single tree stands in the ocean against a pale sunset sky. A banner at the bottom reads
This expedition brought together a wonderfully international group of divers from France, Switzerland, Germany, Romania, the USA, Singapore and Burma, including a very special guest, Thanda Ko Gyi, founder of the Myanmar Ocean Project and the database guru in Myanmar for Mantas both for Manta Trust and Marine Megfauna fondations. Beside education and ghost net removal, her work focuses on manta ray research, identification and conservation in Myanmar waters, adding a meaningful scientific dimension to our journey through one of Southeast Asia’s last true diving frontiers.
From the remote islands of the Mergui Archipelago to the vast offshore plateaus of the Burma Banks, the week unfolded as a perfect balance between encounters with large pelagics and an almost overwhelming richness of macro life.
Scenic aerial view of a turquoise bay and white sand beach in the Mergui Archipelago, Myanmar, surrounded by lush tropical rainforest.
Tropical island scenery in the Mergui Archipelago, Myanmar

Day 1 – From Ranong to the Mergui Archipelago
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After clearing Thai immigration at Badin Pier in Ranong, we welcomed our guests on board before making a smooth crossing to Kawthung for Burmese formalities. Soon after, the Smiling Seahorse headed north into the Mergui Archipelago, where dense jungle-covered islands, quiet anchorages and untouched reefs set the tone for the days ahead.
The MV Smiling Seahorse liveaboard boat cruising on calm blue waters under a bright sky, offering scuba diving trips in Thailand and Myanmar.
The luxurious dive liveaboard MV Smiling Seahorse in the Andaman Sea
A vibrant orange and pink sunset over the horizon of the Andaman Sea during a Myanmar liveaboard diving cruise.
Stunning Andaman Sea sunset during a Myanmar dive safari

Day 2 – High Rock
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Our first immersion at High Rock served as a gentle and colourful introduction to the trip, allowing everyone to settle into the rhythm of diving in Burma.
The reef immediately revealed its macro treasures: long-tail sea hare slugs grazing on the rock, dark margin glossodoris, orange-spotted pipefish weaving through the reef and delicate yellow wentletrap snails (Epitonium billeanum). Flounders rested motionless on sandy patches while cowfish drifted slowly in the current.
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Moray eels were already part of the scenery, with white-eye moray eels and giant moray eels peering from crevices, while schools of juvenile yellowback fusiliers flickered above the reef. In the blue, chevron barracudas held their formation, hinting at the bigger action to come.
The rest of the day unfolded on board with an inspiring presentation by Thanda, sharing insights into manta identification and behaviour, setting the stage for what would become one of the trip’s defining themes.
A close-up of a White Eye Moray Eel peeking out from a hard coral reef in the Mergui Archipelago.
Macro photography of a White Eye Moray Eel in Myanmar | Thierry Lagrave
Macro photography of a White Eye Moray Eel in Myanmar | Thierry Lagrave
Rare Geographic Sea Hare found while scuba diving Black Rock | Thierry Lagrave

Day 3 & 4 – Black Rock

Black Rock delivered its usual blend of raw energy and intricate detail, a place where the blue and the reef constantly compete for attention.
In the open water, oceanic manta rays appeared gracefully, circling above the pinnacle as if inspecting each diver. Thanks to Thanda’s expertise, we were able to identify six different individual manta rays over the course of our dives — a truly special highlight that added a scientific dimension to these encounters.

​Around them, dense formations of chevron and pickhandle barracuda stretched into the distance, while blacktip trevallies, bluefin trevallies, golden trevallies and bigeye trevallies surged through schools of fish in coordinated bursts. Dogtooth tuna and longnose emperors cut through the water column, while massive schools of rabbitfish hovered over the reef.
A giant Oceanic Manta Ray gliding over a colorful soft coral reef at Black Rock in the Mergui Archipelago, Myanmar.
Majestic Manta Ray encounter while diving in Myanmar | Thierry Lagrave
An Oceanic Manta Ray swimming near the surface with several remoras attached, captured during a Smiling Seahorse liveaboard trip.
Oceanic Manta Ray with remoras at a cleaning station | Thierry Lagrave
giant Oceanic Manta Ray swimming past vibrant purple and pink soft corals at Black Rock dive site in the Mergui Archipelago.
Incredible visibility for Manta Ray diving at Black Rock | Thierry Lagrave
Below the action, the reef itself was just as alive. Powder-blue surgeonfish and velvet surgeonfish grazed continuously, while giant moray eels, fimbriated morays, leopard morays and yellow-edged moray eels filled every crack and overhang. Batfish lingered calmly in sheltered zones, seemingly unfazed by the surrounding chaos. Schools of neon fusiliers, scissortail fusiliers and yellowback fusiliers formed thick, shifting clouds wrapping around the rock.
A Goniobranchus geminus nudibranch (twin sea slug) on a vibrant coral reef surrounded by anemones in the Mergui Archipelago.
Vibrant reef biodiversity and nudibranchs in Myanmar | Thierry Lagrave
And then there was the macro.
Black Rock revealed an almost overwhelming diversity: Bornella anguilla, Goniobranchus geometrica, Goniobranchus geminus, Goniobranchus leopardus, Goniobranchus annulata, Risbecia pulchella, gloomy Tamja, white-bump sapsucking slugs, golden wentletrap snails and tiger cowries.
A macro photography shot of a purple and white Goniobranchus geometricus nudibranch on a reef in the Mergui Archipelago.
Discover nudibranches like Gonionbranchus Geometrius on a macro diving safari | Thierry Lagrave
Close-up of a white and yellow spotted Goniobranchus annulatus nudibranch, a highlight for underwater photographers in Myanmar.
Exceptional macro photography opportunities in Myanmar's Mergui Archipelago | Thierry Lagrave
Peacock-tail anemone shrimps, squat shrimps, anemone crabs and peacock mantis shrimps animated the reef, while pharaoh cuttlefish hovered just above the substrate. Stonefish blended perfectly into the rocks and rare sightings of yellow and red clown frogfish added excitement.

​We also encountered Dendrodoris denisoni, orangutan crabs, reef crabs, honeycomb moray eels and Doriprismatica atromarginata. The tiny yet fascinating Trinchesia sibogae showcased its cerata, reminding us of the incredible defensive adaptations of nudibranchs, storing stinging cells from their prey.
A vibrant Trinchesia sibogae nudibranch with bright purple and orange cerata on a reef in the Mergui Archipelago.
Colorful sea slugs of the Andaman Sea | Thierry Lagrave
A high-detail macro shot of a Dendrodoris denisoni nudibranch, showing its unique blue spots and textured body.
Searching for rare macro critters in Myanmar | Thierry Lagrave
Sunset  brought a different atmosphere. Under torchlight, anemone fish hermit crabs, sea urchin crabs, broadclub cuttlefish and pygmy squids emerged, transforming Black Rock into a different world.
A camouflaged Scorpionfish resting among vibrant yellow cup corals on a reef in the Mergui Archipelago.
Master of camouflage: Scorpionfish on a Myanmar reef | Thierry Lagrave
wo bright orange Ocellaris clownfish (Anemonefish) nestled in a purple sea anemone during a dive in the Andaman Sea.
Iconic Anemonefish in the pristine Mergui Archipelago | Thierry Lagrave
A tiny, translucent Pygmy Squid hovering near a red gorgonian sea fan, showcasing the incredible macro life found on a Smiling Seahorse cruise.
Tiny Pygmy Squid: a macro photography highlight

Day 5 – Three Islets & Crossing to the Burma Banks

At Square rock, tigertail seahorses including juveniles clung delicately to the whip coral, while tiger cowries and their eggs decorated the substrate. Schools of yellowtail barracuda passed by as Cuthona sibogae, Hypselodoris decorata and blue dragons brought colour to the reef. Orange-spotted pipefish and cleaner pipefish hovered above the sand while scorpionfish and moray eels remained perfectly camouflaged.
A dark-phase Tiger Tail Seahorse (Hippocampus comes) clinging to an orange sea fan during a dive in the Mergui Archipelago.
Rare Tiger Tail Seahorse sightings in Myanmar | Thierry Lagrave
A bright yellow Tiger Tail Seahorse camouflaged against a rocky reef background in the Andaman Sea.
The signature Tiger Tail Seahorse of the Andaman Sea | Thierry Lagrave
Submarine combined action and detail, with spotted hypselodoris, anemone crabs, stonefish and devil scorpionfish sharing space with bamboo sharks resting under ledges. Schools of juvenile yellowback and scissortail fusiliers mixed with snappers and rainbow runners, while juvenile Koran angelfish and oriental sweetlips added flashes of colour.
A Porcelain Anemone Crab filter-feeding on a hard coral head in the Mergui Archipelago, Myanmar.
Intricate macro life: Anemone Crab on a Myanmar reef | Thierry Lagrave
An Oriental Sweetlips and Copperband Butterflyfish swimming past a massive orange sea fan in the Andaman Sea.
Vibrant coral gardens and reef fish biodiversity
Extreme close-up of a Devil Scorpionfish camouflaged against the reef, showing its textured skin and eye detail.
Incredible reef camouflage: the Devil Scorpionfish | Thierry Lagrave
At Shark Cave, tomato anemonefish and Clark’s anemonefish guarded their homes alongside anemone crabs. White-eye and honeycomb moray eels hid within the reef while macro highlights included Nembrotha lineolata, Cuthona sibogae, mouthbrooding cardinalfish, Chromodoris annulata, skeleton shrimp and camouflaged snapping shrimps.
Macro photography of a tiny, translucent Skeleton Shrimp on a hydroid, captured during a Smiling Seahorse dive trip.
Bizarre macro life: Skeleton Shrimp found in Myanmar | Thierry Lagrave
Two vibrant orange Tomato Anemonefish (Amphiprion frenatus) swimming above their host sea anemone during a dive in Myanmar’s Mergui Archipelago with The Smiling Seahorse.
Vibrant Tomato Anemonefish found on remote Myanmar reefs | Tomato Anemonefish
Our visit to Khyun Pillar Island offered a quiet pause away from the Dive-Eat-Sleep rhythm. Walking through the small Moken village, we experienced a glimpse of a way of life deeply connected to the sea, where tides and seasons shape daily routines. Children played along the beach, longtail boats rested in the shallows, and the surrounding jungle framed the scene with a sense of timelessness. A simple yet meaningful moment that added a human dimension to our journey through this remote Archipelago.
Scenic overlook of Khyun Pillar Island in the Mergui Archipelago, showing a tropical bay with turquoise water and white jasmine flowers in the foreground.
Panoramic view of the remote Khyun Pillar Island in Myanmar
A traditional golden Burmese pagoda (temple) at Khyun Pillar Island against a clear blue sky, a cultural stop on a Myanmar dive liveaboard.
Cultural island excursions during a Myanmar dive cruise
As the sun began to dip, we returned to the water for a night dive rich with life. Blunt decorated crabs, blue eyed rock crabs, cone snails and tiger cowries emerged from hiding, while gorgonian crabs, basket stars and emperor shrimps occupied every corner of the reef. Anemone hermit crabs and squat lobsters moved cautiously between rocks, alongside saw-edged spooner crabs. Sea cucumbers, pencil urchins and sleeping rabbitfish completed the scene, wrapping up the day in a completely different, nocturnal atmosphere.
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That evening, we set course toward the remote Burma Banks...
wo Squat Lobsters (Crab Buddies) hiding in a reef crevice in the Mergui Archipelago, Myanmar.
Commensal crustaceans and reef life in Myanmar | Thierry Lagrave
A detailed macro shot of a sea snail cowrie displaying its mantle over its shell on a colorful reef during a Smiling Seahorse liveaboard trip.
ascinating macro behavior: Cowrie with mantle extended
Extreme close-up of a Giant Moray Eel with its mouth open, showing sharp teeth and textured skin, a common sight at dive sites in Myanmar.
p close with a Giant Moray Eel at Black Rock | Thierry Lagrave

Day 6 – Burma Banks

Row Bank introduced us immediately to the signature atmosphere of the Banks. Nurse sharks dominated the dives, resting on sandy ledges or gliding slowly past divers. Around them, powder-blue surgeonfish, lined surgeonfish, oriental sweetlips and two-spot butterflyfish filled the reef. Coral groupers and peacock groupers held their territories while cleaner wrasse and sixline wrasse worked tirelessly. Basslets hovered close to the reef face and yellow saddle goatfish sifted through the sand.
A large Nurse Shark swimming low over a rocky reef during a dive in the Mergui Archipelago, Myanmar.
Exciting shark encounters in the Mergui Archipelago | Thierry Lagrave
At Rainbow Bank, the pelagic energy increased. More nurse sharks rested across the plateau while schools of humpback unicornfish and sleek unicornfish moved in formation. Batfish, longnose emperors and large schools of black-and-white snappers mixed with giant one-spot and five-lined snappers. Great barracuda patrolled the edges while honeycomb moray eels filled the reef.
A large school of sleek Unicornfish swimming past a dramatic rock pinnacle in the Mergui Archipelago, Myanmar.
Explore the rich marine biodiversity of the Mergui Archipelago on a dive cruise.
A solitary Great Barracuda patrolling over a healthy soft coral reef in the Andaman Sea.
Encounter apex predators while diving the pristine reefs of the Burma Banks.
 Blackwater  dives added a completely different dimension: sea angels mating, crab zoea larvae drifting, larval sleeper lobsters, flying fish larvae, eel larvae, salps, eternal jellyfish and juvenile  female paper nautilus drifting like tiny living sculptures.
A transparent larval eel drifting in the open ocean at night, captured during a specialized blackwater dive in Myanmar.
Discover alien-like creatures with our signature Myanmar blackwater diving expeditions. | Thierry Lagrave
A stunning macro photo of a juvenile Flying Fish with expanded fins against a pitch-black background during a blackwater drift.
Award-winning macro photography opportunities on a blackwater dive in Myanmar. | Thierry Lagrave
Rare macro photography of two translucent Sea Angels mating during a blackwater dive in the Mergui Archipelago, Myanmar.
Rare marine life behavior: Mating Sea Angels on a Myanmar blackwater drift. | Thierry Lagrave
A tiny Eternal Jellyfish (Turritopsis dohrnii) with long stinging tentacles glowing against a black background during a blackwater dive in Myanmar.
Witness the immortal Eternal Jellyfish on a Myanmar blackwater dive | Thierry Lagrave
A rare Female Paper Nautilus (Argonaut) drifting in the open ocean during a blackwater diving expedition in the Andaman Sea.
Rare Paper Nautilus encounter during a blackwater dive | Thierry Lagrave

Day 7 – Burma Banks
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Coral Bank delivered one of the most intense sequences of the banks for most of our divers. Nurse sharks swam directly through the group, while a massive mangrove whip ray lifted off from the reef and glided effortlessly past divers. Grey reef sharks appeared in the blue, replacing the nurse sharks as the dominant presence. Giant barracuda, large tuna, a hawksbill turtle, and huge schools of trevallies, snappers, fusiliers, parrotfish and surgeonfish surrounded us in every direction.
A Hawksbill sea turtle feeding on a rocky reef with scuba divers in the background during a Smiling Seahorse liveaboard trip in Myanmar.
Sustainable dive tourism: Passive Hawksbill Turtle encounter in Myanmar
A massive school of Big Eye Trevally (jacks) swimming in clear blue water with sunbeams piercing the surface in the Mergui Archipelago.
Incredible fish biomass and schooling Trevally in the Andaman Sea | School of Big Eye Trevally
At Silvertip Bank, the action continued with nurse sharks and an abundance of reef life: scalefin anthias, redbar anthias, coral groupers, titan triggerfish, bird wrasse, raccoon butterflyfish, regal angelfish and blue-spined unicornfish moving across the reef.

During our navigation between dive sites, we were joined by a playful pod of dolphins riding the bow wave, effortlessly gliding alongside the boat and occasionally darting ahead before looping back again. One of those simple yet unforgettable moments that perfectly captures life at sea.
Three wild dolphins swimming in the bow wake of The Smiling Seahorse liveaboard in the deep blue waters of the Andaman Sea.
Magical wildlife encounters: Dolphins bow-riding during a Myanmar dive safari.
Blackwater dives revealed yet more pelagic wonders: barracuda larvae, flying fish, mantis shrimp larvae, shrimp larvae, dragonfish, glowing pyrosomes and drifting pencil squid completing the surreal night scene.
A tiny, translucent juvenile Great Barracuda drifting in the open ocean during a blackwater diving trip in Myanmar with The Smiling Seahorse.
High-detail macro photography of a juvenile Barracuda in blackwater | Thierry Lagrave
A glowing bioluminescent Pyrosome colonial tunicate with small juvenile fish hitching a ride, captured during a blackwater drift in the Andaman Sea.
Rare bioluminescent Pyrosome encounters in the Andaman Sea | Thierry Lagrave
A small juvenile fish seeking protection inside the transparent body of a Comb Jelly (Ctenophore) during a blackwater dive in the Mergui Archipelago.
Unique marine life symbiosis: Juvenile fish sheltered in a Comb Jelly | Thierry Lagrave
A small Pencil Squid with shimmering skin captured during a night blackwater dive in the Mergui Archipelago, Myanmar.
Incredible cephalopod encounters: Pencil Squid in blackwater | Thierry Lagrave
A transparent larval Dragon Fish with unique elongated features drifting in the open ocean during a blackwater safari.
Rare deep-sea larval Dragon Fish found in Myanmar | Thierry Lagrave

Day 8 – Seafan Forest & Western Rocky

Seafan Forest offered a calmer but still beautiful dive, where large purple sea fans and soft coral trees swayed gently in the current. Stonefish rested perfectly camouflaged among the reef, while schools of yellowback fusiliers and neon fusiliers drifted past. Coral groupers and peacock groupers hovered near the reef, joined by powder-blue surgeonfish, Indian sailfin tang and clouds of anthias adding colour to the scene.
A perfectly camouflaged Reef Stonefish hiding among pink soft corals and orange cup corals on a reef in the Mergui Archipelago.
Expertly camouflaged Stonefish on a healthy Myanmar reef
A giant orange gorgonian sea fan surrounded by pink soft corals and a school of small reef fish in the Andaman Sea.
Discover the stunning seafan forests of Western Rocky
A vibrant school of blue and yellow Neon Fusiliers swimming over a hard coral reef in the crystal clear waters of Myanmar.
Experience incredible fish action and vibrant coral reefs in the Mergui Archipelago.
At Western Rocky, the dives brought back a mix of macro and schooling fish, creating a perfect balance to end the trip. Inside the cave, a stonefish guarded the exit while giant moray eels watched from the shadows. Outside, ghostpipefish hovered near the islets and blue dragons and Chromodoris annulata added delicate splashes of colour to the reef.

​Schools of fusiliers — including yellowback, twin stripe and neon fusiliers — mixed with giant trevallies, bluefin trevallies and passing barracuda circling the formations. Lionfish, scorpionfish and titan triggerfish filled the reef, while cleaner shrimps and squat shrimps animated the cracks, bringing the macro world back into focus.
A white Doriprismatica atromarginata nudibranch with a distinct black border crawling on a reef in the Mergui Archipelago.
Macro critter hunting: the elegant Black-Margined Nudibranch | Thierry Lagrave
A macro photography shot of a tiny Porcelain Crab hiding under a rocky ledge on a vibrant Myanmar dive site.
Exceptional macro photography details on a Myanmar dive safari | Thierry Lagrave
A large Titan Triggerfish swimming through a massive school of glassfish in the deep blue waters of the Andaman Sea.
Witness the incredible marine biomass of the Mergui Archipelago on a luxury liveaboard cruise.
As the evening started, under a calm, star-filled sky, we gathered on the upper deck for our traditional BBQ.
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Stories from the trip flowed naturally between us — manta encounters at Black Rock, close passes with sharks on the Banks, and the countless macro discoveries that had kept everyone’s eyes glued to the reef. Laughter, shared moments and quiet reflections blended together, as plates filled and emptied and glasses were raised one last time.

Manta Ray at Black Rock | Camille Rovillain 
As the evening unfolded, the mood shifted from relaxed to celebratory. Music floated through the air and before long, the upper deck turned into an open-air dance floor. Barefoot under the stars, surrounded by the ocean, the night carried on with energy, laughter and dancing — the perfect way to celebrate a week that had delivered both unforgettable big encounters and the smallest hidden wonders.
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It was more than just a dinner; it became a true celebration of the journey we had shared — from the vast blue of the Burma Banks to the intricate beauty of the reefs — a perfect closing chapter before returning to shore.
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Andaman Sea Scuba Diving Liveaboard Myanmar​
A golden tropical sunset over a silhouetted island limestone karst in the Mergui Archipelago, Myanmar, during a dive cruise.
Unforgettable tropical sunsets over the Mergui Archipelago
A delicious gourmet BBQ dinner spread featuring grilled meats and corn on the cob served aboard The Smiling Seahorse liveaboard.
Fresh gourmet dining and BBQ nights on a Myanmar liveaboard cruise

Day 9 – Dendro’s Peak & Farewell
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The final dive at Dendro’s Peak wrapped up the trip with a blend of everything we had experienced. Nudibranchs decorated the reef while fimbriated moray eels peered from crevices. Batfish hovered in the current and trevallies passed through the blue.
A bright yellow Giant Frogfish camouflaged on a rocky reef in the Mergui Archipelago, a prize find for underwater photographers in Myanmar.
Rare macro sightings: A Giant Frogfish in the Mergui Archipelago | Thanda Ko Gyi
Close-up of a small Blenny peering out from its burrow in a coral reef during a dive trip with The Smiling Seahorse.
Discover the charming macro life of the Andaman Sea | Thierry Lagrave
Two tiny spider crabs camouflaged on a red sea fan, illustrating the incredible biodiversity found on Myanmar’s remote reefs.
Hidden treasures: Camouflaged Crabs on a sea fan | Thierry Lagrave
After surfacing, we made our way back to Kawthoung for Burmese immigration, shared a final drink at the Smile Bar and returned to Ranong, closing another unforgettable journey through the Mergui Archipelago and the Burma Banks aboard the MV Smiling Seahorse.
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​Beyond the incredible encounters — from six individually identified manta rays at Black Rock to the endless diversity of nudibranchs and reef life — this trip also carried a deeper meaning. With Thanda on board, every sighting became part of a bigger picture, contributing to the understanding and protection of marine life in Myanmar waters.
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It was a reminder that these remote ecosystems are not only places of beauty and adventure, but also fragile environments that depend on awareness, research and responsible diving. Exploring them is a privilege — helping to protect them is part of the journey.

Until the next tide brings us together again — dive well, dive aware, and see you soon, fellow divers.
A group of four scuba divers posing together in mid-water during a liveaboard trip in the Mergui Archipelago, Myanmar.
Making memories with new dive buddies in the Andaman Sea
]]><![CDATA[Trip report | 1st – 8th March 2026 | South & North Andaman Expedition]]>Fri, 13 Mar 2026 07:00:42 GMThttps://www.thesmilingseahorse.com/blog/trip-report-1st-8th-march-2026-south-north-andaman-expedition
The Smiling Seahorse liveaboard boat at sunset in the Mergui Archipelago, Myanmar, featuring a trip report from March 2026.
​From rugged cliffs rising out of turquoise water to remote reefs pulsing with life, the Andaman Sea always rewards those who explore it patiently.
This week’s itinerary took us on a beautiful journey from the limestone islands of the South Andaman up to the vibrant reefs of the North Andaman. From Koh Phi Phi and Koh Lanta to the Similan and Surin National Parks, the route offered a wonderful contrast between dramatic pelagic encounters and intricate macro life hiding in the reefs.
A massive school of Chevron Barracuda swirling near Koh Bida Nok in Phi Phi National Park, Thailand.
Epic schooling action at Koh Bida Nok: Chevron Barracuda in Phi Phi National Park.
Lush pink soft corals and sea fans covering the limestone walls of Koh Bida Nai, Thailand.
Vibrant soft coral gardens: Diving the iconic walls of Phi Phi National Park | Itai Grisaru

Day 1 – From Phuket to Koh Phi Phi National Park
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​We departed from Charter Marine Pier in Phuket together with our Dive Buddy guests from Israel and began sailing toward the famous Phi Phi Islands. The Phi Phi National Park is known not only for its spectacular limestone cliffs rising straight out of pristine waters, but also for its vibrant coral reefs and sheltered bays that host a wide diversity of marine life. After a relaxed evening at anchor beneath towering cliffs, everyone was eager to begin diving the following morning.

Ready To Dive | Vélika Marquis

​Day 2 – Koh Phi Phi National Park & Koh Lanta National Park

Our check dive at Koh Bida Nok immediately reminded us why this site is so popular. Blacktip reef sharks cruised calmly along the reef edge while a tigertail seahorse and a ghostpipefish provided the first macro highlights of the trip. Flounders rested on sandy patches while feather seastars walked slowly across the reef. Schools of snappers gathered around coral heads and several Phyllidia species appeared alongside Hypselodoris bullocki, Hypselodoris iacula and purple-spotted Hypselodoris.
Purple urchin shrimps hid among spines, while banded sea snakes moved gracefully between rocks. A snowflake moray eel peeked from its shelter and Goniobranchus fidelis, Flabellina rubrolineata and decorator crabs added colourful details to the reef. Around us swam coral groupers, peacock groupers, powder-blue surgeonfish, threadfin butterflyfish and schools of yellowback fusiliers moving through healthy coral gardens.
A Banded Sea Krait (Laticauda colubrina) hunting along the sandy bottom of a coral reef in Phi Phi National Park, Thailand.
arine life encounters in the Andaman Sea: The venomous yet docile Banded Sea Krait
A Ghost Pipefish perfectly camouflaged against colorful soft corals during a dive in the Phi Phi Islands, Thailand.
Rare macro finds in Thailand: The Ghost Pipefish | Ghost Pipefish | Itai Grisaru
The iconic limestone lagoons of Koh Haa in Mu Ko Lanta National Park, Thailand, a premier destination for South Andaman liveaboards.
Sailing through the breathtaking lagoons of Koh Haa | South Andaman | Thailand
A vibrant purple Hypselodoris bullocki nudibranch on a reef at Koh Haa, Thailand, captured during a Smiling Seahorse dive cruise.
Stunning macro biodiversity: Hypselodoris Bullocki Nudibranch | Itai Grisaru
A Blacktip Reef Shark (Carcharhinus melanopterus) patrolling the rocky slopes of Koh Haa Yai in the South Andaman Sea.
Shark sightings in the South Andaman: Blacktip Reef Shark at Koh Haa
​The second dive took place in the calm Koh Haa Lagoon. A giant moray eel rested beneath coral bommies while juvenile clown triggerfish hovered nearby. A passing blacktip reef shark cruised over the sand as blue dragons glided along the reef. Macro highlights included Glossodoris rufomarginata, Halgerda tesselata, Janolus sp., Andaman jawfish and cardinalfish carrying eggs in their mouths. Bluestreak cleaner wrasse performed their cleaning dances while bicolor blennies watched from coral holes. Squat shrimps and lobsters shared rocky crevices as razor wrasse flashed across the reef
​The third dive brought us to the famous Koh Haa Cathedral, where shafts of sunlight illuminated the cavern. A juvenile hawksbill turtle glided slowly through the entrance while nudibranchs decorated the walls: Glossodoris hikuerensis, Bornella anguilla, Goniobranchus reticulata, Halgerda tesselata, Hypselodoris sp. and Glossodoris atromarginata. Skeleton shrimps clung to hydroids and a tiger cowrie rested beneath a coral ledge.
A pair of colorful Halgerda tesselata nudibranchs on a sponge-covered reef at Koh Haa, Mu Ko Lanta National Park, Thailand.
Exquisite macro details of Koh Haa: Halgerda Tesselata Nudibranch | Itai Grisaru
A Hawksbill sea turtle swimming over a coral reef at Koh Haa, with a snorkeler silhouetted on the surface in the Andaman Sea.
Graceful reef residents: Hawksbill Turtle at Koh Haa | Mu Ko Lanta National Park
Aerial view of The Smiling Seahorse liveaboard boat anchored at Hin Daeng (Red Rock) during a golden sunset in Mu Ko Lanta National Park, Thailand.
Sunset at the world-famous Hin Daeng dive site | Udi Nehab
​Our night dive at Hin Daeng transformed the reef into a hunting ground. A giant moray eel prowled through the darkness while red reef crabs and ornamental spider crabs emerged from hiding. A red abalone rested on the rock and comb seastars stretched across the reef surface. Batfish and great barracuda passed slowly through the torchlight while Clark’s anemonefish guarded their eggs. Anemone hermit crabs and anemone crabs shared their hosts and a splendid red spooner crab waved its arms across the reef. Nearby, an ornate sap-sucking slug (Elysia) grazed along the coral.

Day 3 – Koh Lanta National Park
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​The morning began at Koh Rock, where colourful reefs hosted large schools of parrotfish and wrasses. A rare big feathertail stingray glided across the sandy bottom while a mimic phyllidia nudibranch rested beside Hypselodoris jacksoni. Stonefish blended perfectly into the reef and a banded sea snake moved slowly between coral heads. Clark’s anemonefish nurtured their eggs while anemone crabs guarded their homes.
Goniobranchus geminus, script flatworms, bluefin trevally and dragonets appeared across the reef. Lobsters hid beneath rocks while hairy shrimps, whip coral cowries, Flabellina rubrolineata, blue dragons and Ceratosoma tribolatum added a beautiful macro layer.
A colorful Goniobranchus geminus nudibranch crawling on a sponge-covered reef in Mu Ko Lanta National Park, Thailand.
Gem Nudibranch macro details: Goniobranchus Geminus | Itai Grisaru
An incredibly small and rare Hairy Shrimp (Phycocaris simulans) camouflaged on a reef during a dive in the South Andaman Sea.
Rare macro treasures of Thailand: The elusive Hairy Shrimp | Itai Grisaru
Extreme close-up of a Clark's Anemonefish guarding a batch of orange eggs on a rock near its host anemone in Koh Lanta National Park.
Marine life behavior: Anemonefish tending to its eggs in the South Andaman Sea.
A Giant Moray Eel resting in a crevice under vibrant pink soft corals at Hin Muang in Mu Ko Lanta National Park, Thailand.
Exploring the purple reefs of Hin Muang: Giant Moray Eel sheltered by soft corals
A colorful Flabellina rubrolineata nudibranch with bright purple and orange cerata crawling on hydroids in the South Andaman Sea.
Vibrant macro life: The stunning Flabellina Rubrolineata nudibranch | Itai Grisaru
​At Hin Daeng, the reef exploded with life. Juvenile emperor angelfish shimmered in yellow and blue while tiger cowries rested beneath coral ledges. Barracudas circled above the reef while Goniobranchus reticulata, Goniobranchus geometrica and spotted Hypselodoris decorated the walls. Giant moray eels and bartail morays hid among cracks where masked porcupinefish shared shelters with banded boxer shrimps. Batfish cruised past while turtles, ghostpipefish, yellow-margin moray eels and mackerels passed through the blue.
​The third dive at Koh Haa Neua – the Chimney delivered exceptional macro life. Glossodoris cincta, ghostpipefish, tiger egg cowries, Cuthona sibogae, Bornella anguilla, ornate sap-sucking slugs and Moridilla brocki decorated the walls. Hypselodoris maculosa, Hypselodoris whitei, Caloria indica and bicolor flabellina added vibrant colours while lobsters hid between rocks. Schools of yellowback fusiliers and lunar fusiliers swirled above the reef together with copperband butterflyfish, Indian sailfin tang, coral grouper and blue-striped snappers.
After the final dive, we began our northern crossing toward the Similan National Park.
A Juvenile Emperor Angelfish with its striking blue and white circular patterns swimming near a reef in the South Andaman Sea, Thailand.
The mesmerizing patterns of a Juvenile Emperor Angelfish
A vibrant school of yellowback fusiliers darting through the clear blue waters of Mu Ko Lanta National Park.
Non-stop fish action: Schooling Fusiliers in the South Andaman Sea.
A stunning wide-angle fisheye shot of a massive pink soft coral colony blooming at Hin Muang, Thailand.
Diving "Purple Rock": The lush soft coral reefs of Hin Muang | Itai Grisaru

Day 4 – Similan National Park
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​Our first dive took place in Honeymoon Bay, where a large Jenkins ray rested peacefully on the sandy bottom.
At Tuna Wreck and Hideaway Reef, excellent visibility revealed giant sweetlips, a curious Napoleon wrasse and a delicate pygmy pipehorse. The psychedelic batwing slug added colour to the reef while schools of yellowback fusiliers, twinstripe fusiliers and blue-striped snappers swirled above the wreck. Coral groupers, powder-blue surgeonfish, threadfin butterflyfish and oriental sweetlips patrolled the reef.
A large green Napoleon Wrasse (Humphead Wrasse) swimming past a reef pinnacle in the South Andaman Sea, Thailand.
Majestic reef giants: A Napoleon Wrasse encounter in the Andaman Sea
The stern of the Tuna Wreck, a popular sunken ship for scuba diving near the Similan Islands and Phi Phi, encrusted with marine life.
Wreck diving adventures in Thailand: Exploring the Tuna Wreck | Itai Grisaru
A rare Kyonemichthys rumengani pygmy pipehorse, also known as the Lembeh Pipehorse, camouflaged on a reef in the South Andaman Sea.
Rare macro discovery: The elusive Kyonemichthys rumengani pygmy pipehorse | Itai Grisaru
​At West of Eden, the macro world shined once again. A psychedelic batwing slug and kissing pygmy pipehorses were highlights, while a mantis shrimp watched from its burrow. Squat shrimps, darkspotted flatworms and Xenia crabs decorated the reef and MacKosker’s flasher wrasse flashed bright colours. Pipefish hovered in the current and during our surface interval a giant green turtle swam right beside the boat to greet us.
Green Turtle Visits the Boat| Camille Rovillain
​The night dive at Honeymoon Bay was full of activity. Trevallies hunted among schools of small reef fish while porcupinefish and pufferfish cruised slowly through the sand patches. Barracudas passed in the distance while red reef crabs carrying eggs moved across the reef. Moray eels hunted actively and sleeping parrotfish and wrasses rested beneath coral ledges.
A Psychedelic Batwing Sea Slug (Sagaminopteron psychedelicum) crawling on a purple sponge in the Similan Islands, Thailand.
Similan macro specialties: The vibrant Psychedelic Batwing Sea Slug | Itai Grisaru
A colorful Peacock Mantis Shrimp (Odontodactylus scyllarus) peering out from its burrow on a reef in Mu Ko Similan National Park.
Fierce reef predators: The colorful Peacock Mantis Shrimp in the Similans

Day 5 – Similan National Park
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​At Deep Six, a whitetip reef shark cruised the reef while a turtle swam past granite boulders. An octopus shifted colours across the rocks while blue dragons and psychedelic batwing slugs decorated the reef. Powder-blue surgeonfish, copperband butterflyfish, oriental sweetlips and schools of neon fusiliers filled the water column.
Elephant Head Rock delivered dramatic granite formations. A blue ribbon eel waved from its burrow while an octopus explored the reef. Bornella anguilla and blue dragons appeared on the rocks beside an adult yellow boxfish. Giant trevallies and bluefin trevallies cruised through the arches while surgeonfish and oriental sweetlips gathered around coral heads. A giant moray eel watched divers from its cave.
A unique Bornella anguilla nudibranch, known for its eel-like swimming motion, on a reef in the Similan Islands, Thailand.
Rare "Swimming Nudibranch" sightings: Bornella Anguilla in the Similans | Itai Grisaru
A dense school of Barracuda silhouetted against the bright surface of the Andaman Sea at a dive site in Mu Ko Similan National Park.
Thrilling fish schools: Barracuda action during our Similan Islands cruise
​At Three Trees, a school of barracuda hovered in the blue above giant sweetlips and garden eels. Blue-spotted Kuhls rays rested on the sand and a giant barrel sponge dominated the reef structure. Schools of blue-lined snappers, yellowback fusiliers and scissortail fusiliers moved constantly across the reef.
​That evening’s blackwater dive was spectacular: male and female paper nautilus drifting gracefully, juvenile porcupinefish, squirrelfish larvae, squids, flounders and even a flying gurnard drifting through the beam of our lights.
A rare tiny male Paper Nautilus (Argonauta) drifting in the open ocean during a blackwater dive in the Similan Islands, Thailand.
Rare blackwater treasures: A tiny male Paper Nautilus drifting in the Andaman Sea.
A translucent larval shrimp captured against a black background during a blackwater drift dive in Thailand with The Smiling Seahorse.
Alien-like larval forms: Discovering the "planktonic soup" on a blackwater drift | Itai Grisaru
A completely transparent juvenile Acanthuridae (Surgeonfish) in its larval stage, showing visible skeletal structure during a blackwater dive.
The transparent beauty of a larval Surgeonfish (Acanthuridae) in blackwater | Itai Grisaru
A bioluminescent polychaete worm drifting in the dark open ocean during a blackwater diving session in Thailand.
The "night shift" of the Andaman Sea: Bioluminescent worms in blackwater | Itai Grisaru
A tiny, shimmering juvenile squid captured with macro photography against a black background during a night drift in the Similan Islands.
Incredible cephalopod macro details from our Similan blackwater dives | Itai Grisaru
A high-detail macro shot of a juvenile Flying Gurnard with its pectoral fins tucked in, found drifting in the Andaman Sea.
Unique blackwater encounters: Larval Flying Gurnard at night | Itai Grisaru
A rare larval Heteropod (sea snail) with a translucent shell drifting in the open ocean during a blackwater dive in the Similan Islands.
Pelagic mollusks of the Andaman Sea: The fascinating Larval Heteropod | Itai Grisaru
transparent larval Cusk Eel showing its delicate fins and internal structure against the black background of a night drift dive in Thailand.
Alien-like larval forms: Discovering the rare Cusk Eel in blackwater | Itai Grisaru
A tiny, round juvenile Porcupine Fish (Diodontidae) captured during a blackwater expedition in the Similan Islands, Thailand.
Adorable macro finds: A juvenile Porcupine Fish drifting in the deep blue | Itai Grisaru

Day 6 – Similan National Park
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​At Koh Bon Ridge, schools of barracuda circled above giant trevallies and bluefin trevallies. Damselfish, butterflyfish and two-tone dartfish hovered above the reef while Clark’s anemonefish guarded their homes. Titan triggerfish, redtooth triggerfish and the distinctive “WiFi triggerfish” moved across the reef alongside pajama surgeonfish. Nudibranchs such as Haminoea cymbalum and Chelidonura hirundinina and Chelidonura punctata decorated the sand while a banded sea snake slithered past. Andaman sweetlips hovered near coral ledges.
A tiny Haminoea cymbalum (Bubble Snail) with a mint-green body and bright orange spots on a reef in the Similan Islands, Thailand.
Vibrant macro treasures: The colorful Haminoea Cymbalum nudibranch in the Similans | Itai Grisaru
A Squat Shrimp (Thor amboinensis), also known as a Sexy Shrimp, performing its characteristic tail-bobbing on an anemone in Mu Ko Similan National Park.
Reef "dancers": The charismatic Squat Shrimp found on a Similan dive | Udi Nehab
​Koh Tachai Plateau was spectacular. Blacktip sharks and Jenkins rays cruised across the plateau while a massive school of chevron barracuda filled the blue. Giant trevallies, bigeye trevallies, dogtooth tuna and rainbow runners hunted actively. Giant marble groupers rested near coral bommies while yellowback and neon fusiliers formed massive clouds above the reef. A juvenile hawksbill turtle swam past and clown triggerfish hovered near coral heads while whip coral gobies hid among gorgonians.
Three happy scuba divers relaxing on the deck of The Smiling Seahorse liveaboard during a North and South Andaman cruise in Thailand.
Good vibes only: Sharing dive stories with the dream team on board | Itai Grisaru
An underwater photographer using a professional camera rig to capture vibrant orange sea fans and pink soft corals in the Similan Islands.
Capturing the magic: An underwater photographer exploring the colorful reefs of Thailand | Itai Grisaru
​On the third dive from the third pinnacle to the main plateau we encountered two more Jenkins rays, a curious Napoleon wrasse and two octopuses flirting among the rocks. Giant trevallies and bluefin trevallies cruised through dense schools of yellowback fusiliers while giant moray eels and batfish watched from the reef.
The night dive on Koh Tachai Reef revealed Glossodoris, Elysia species and Halgerda tesselata. A blacktip reef shark cruised through the darkness while a giant moray eel hunted along the reef.
A Doriprismatica atromarginata nudibranch laying a white spiral egg ribbon on a reef at Koh Tachai, Mu Ko Similan National Park, Thailand.
Fascinating marine life behavior: A Doriprismatica nudibranch laying eggs at Koh Tachai | Itai Grisaru
Spotted Garden Eels (Heteroconger hassi) swaying in the current above the sandy seabed at the Koh Tachai plateau, Thailand.
Swaying in the current: Spotted Garden Eels at Koh Tachai | Itai Grisaru

Day 7 – Surin National Park
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​We returned to Richelieu Rock for three spectacular dives. Purple soft corals covered the pinnacle while glassfish formed shimmering clouds around the rock. Harlequin shrimps, ghostpipefish and thorny seahorses delighted macro lovers while Durban dancing shrimps, orange-spotted pipefish and cleaner pipefish filled the reef with activity.
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Giant trevallies and the famous Richelieu “gang” — rainbow runners, trevallies and longnose emperors — hunted through the schools of fish. Barracudas formed impressive formations including chevron, yellowtail and pickhandle barracuda. Peacock mantis shrimps, banded boxer shrimps and blue-legged boxer shrimps decorated the reef while giant moray eels and a zebra moray eel emerged from their holes. Scorpionfish and devil scorpionfish rested on the reef while batfish and juvenile emperor angelfish cruised nearby.
A yellow Tigertail Seahorse (Hippocampus comes) clinging to a purple sea fan at Richelieu Rock, Surin Islands, Thailand.
The golden residents of Richelieu Rock: A beautiful Tigertail Seahorse | Itai Grisaru
glassfish coral A massive cloud of translucent Glassfish swarming over a colorful coral pinnacle at Richelieu Rock in Mu Ko Surin National Park.reef itai grisaru Thailand Andaman Liveaboard Scuba Diving Cruise
Underwater blizzards: Shimmering Glassfish clouds at Richelieu Rock | Itai Grisaru
A wide-angle fisheye view of a giant orange sea fan surrounded by colorful soft corals and Anemonefish at Richelieu Rock, Thailand.
Vibrant reef architecture: The iconic giant sea fans of Richelieu Rock | Itai Grisaru
A tiny Whip Coral Shrimp (Pontonides ankeri) perfectly camouflaged on a wire coral during a dive in Mu Ko Surin National Park.
Hidden in plain sight: A Whip Coral Shrimp on its host | Itai Grisaru
A pair of ornate Harlequin Shrimp (Hymenocera picta) feeding on a sea star at Richelieu Rock, a top sighting for macro photographers in Thailand.
The ultimate macro find: Harlequin Shrimp at Richelieu Rock | Itai Grisaru
​Our sunset dive at Ao Pakard (Cabbage Bay) revealed a vibrant coral reef. A hawksbill turtle swam slowly past while schools of juvenile barracuda hovered above the reef. Sailfin tang surgeonfish grazed alongside yellow saddle goatfish, angelfish and triggerfish. Kuhls blue-spotted stingrays rested on the sand while blue dragons, juvenile scorpionfish and juvenile mantis shrimps appeared among coral rubble.

Day 8 – Return to Ranong
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​The final morning began at Torinla Pinnacle, where Koran angelfish swam alongside surgeonfish, butterflyfish and giant moray eels. A whitetip shark slept beneath a rock while a school of bumphead parrotfish passed slowly through the reef. Kuhls blue-spotted rays glided across the sandy patches and a bright yellow “Pikachu” nudibranch delighted photographers.

The Richelieu Rock "Gang" | Udi Nehab

​For the final dive at Richelieu Rock, the reef delivered a grand finale. The gang returned once more: trevallies, longnose emperors and a ball of jacks swirling through the water column. Barracudas formed impressive schools while juvenile clown triggerfish and juvenile emperor angelfish hovered over the reef. Thorny seahorses, ghostpipefish and tiger cowries with their eggs decorated the coral. Hypselodoris decorata, dark-margin glossodoris and blue dragons added colour while peacock mantis shrimps guarded their burrows. Schools of yellowback fusiliers, lunar fusiliers and manylined fusiliers filled the water column above coral groupers, copperband butterflyfish and powder-blue surgeonfish.
​Soon after surfacing, we began sailing back toward Ranong — closing another unforgettable Andaman adventure aboard the MV Smiling Seahorse.
Until the next tide brings us together again — dive well, dive aware, and see you soon fellow divers.
A group of smiling scuba divers and crew enjoying drinks and fresh passion fruit on the deck of The Smiling Seahorse liveaboard in Thailand.
Post-dive celebrations: Relaxing with the best crew in the Andaman Sea | Happy Divers!
underwater photographer Itai Grisaru geared up and ready for a night dive on a Thailand liveaboard cruise.
Behind the lens: The talented Itai Grisaru ready for more underwater magic
Scuba divers Udi Nehab and Yiftah Shelef smiling in their dive gear before a sunset dive in the Similan Islands, Thailand.
Making lifelong connections: Photographer Udi Nehab and Dive Buddy Yiftah Shelef
Photography by Franck Fogarolo, Itai Grisaru, Udi Nehab and Vélika Marquis​
Videography by Camille Rovillain and Vélika Marquis
]]><![CDATA[Trip report, 20th–27th February 2026, Thailand North and South Andaman Excursion]]>Mon, 02 Mar 2026 02:49:01 GMThttps://www.thesmilingseahorse.com/blog/trip-report-20th-27th-february-2026-thailand-north-and-south-andaman-excursion
Batwing Sea Slug Itai Grisaru Thailand Scuba Diving Liveaboard
Batwing Sea Slug | Itai Grisaru
Some trips lean toward pelagic action. Others toward patient macro exploration. This North to South Andaman crossing gave us both.
This North-to-South Andaman expedition took us through four marine national parks — Surin, Similan, Koh Lanta and Tarutao — before finishing in Phuket. A true cross-section of Thailand’s Andaman Sea. 

This trip became a beautiful contrast between “the big” and “the small” — manta encounters, shark sightings and hunting trevallies on one side… and delicate nudibranchs, shrimps and ghost pipefish on the other.
Bait Ball and Big Eye Trevally Thailand Scuba Diving Liveaboard
Big Eye Trevally Swimming Into a Bait Ball
Shore visit on the dinghy Thailand Scuba Diving Liveaboard
Shore Visits on the Dinghy
Surface view Thailand Scuba Diving Liveaboard
A View From the Surface
Big Eye Trevally Hunting Thailand Scuba Diving Liveaboard
Big Eye Trevally Hunting

Day 1 – From Ranong to Surin National Park

We welcomed our divers from Buddy Divers Israel in Ranong and began our journey southward. The route would take us through Surin National Park first, then down to the Similan Islands, further south to Koh Lanta and Tarutao, before heading back north toward Phuket.
A true Andaman traverse...

Day 2 – Surin National Park

Our check dive at Koh Chi Reef offered calm conditions and crystal-clear visibility. The Surin Islands, home to the Moken sea nomads, are known for their gentle sandy slopes and vibrant coral gardens.
 
False anemonefish and Clark’s anemonefish hovered over magnificent sea anemones while moray eels peered from coral heads. Schools of five-lined snappers moved in tight formation above the reef. Blue-barred parrotfish and bullethead parrotfish grazed over staghorn coral and honeycomb coral formations.
 
Cleaner wrasse, moon wrasse and sixline wrasse worked busily along the reef, while hawksbill turtles glided past. Slender Roboastra, orange-spotted Chelidonura, sea cucumbers, black diadema sea urchins and feather stars dotted the seabed.
Anemonefish Thailand Scuba Diving Liveaboard
Anemonefish
turtle Thailand Scuba Diving Liveaboard
Turtle
reef fish Itai Grisaru Thailand Scuba Diving Liveaboard
Reef Fish | Itai Grisaru
Then came Richelieu Rock.
 
If there is a place where “big versus macro” truly coexist, it is here.
 
The “gang” was in full hunting mode: giant trevallies, bluefin trevallies, bigeye trevallies and massive schools of rainbow runners sweeping through clouds of glassfish. Yellowtail and chevron barracudas cruised the perimeter. A shy black manta passed in the blue for one lucky group.
Richelieu Rock Hunting Fish Thailand Scuba Diving Liveaboard
Feeding Frenzy at Richelieu Rock
Richelieu Rock Hunting Fish Thailand Scuba Diving Liveaboard
"The Gang" Hunting at Richelieu Rock
Black oceanic manta ray Thailand Scuba Diving Liveaboard
Black Oceanic Manta Ray
White-eye, fimbriated and giant moray eels filled nearly every crack. Yellowback fusiliers and two-spot fusiliers swirled above schools of five-lined snappers.

 Meanwhile, macro lovers were glued to the rock: Chromodoris annulata, Cuthona sibogae, Chromodoris geometrica, slender Roboastra, and delicate thorny seahorse and a couple of harlequin shrimps hiding into pink and purple soft corals covering the pinnacle.
Thorny Seahorse Thailand Scuba Diving Liveaboard
Thorny Seahorse
Flabellina nudibranch Itai Grisaru Thailand Scuba Diving Liveaboard
Flabellina Nudibranch | Itai Grisaru
The night dive shifted the mood completely. Glossodoris atromarginata, orange-tip Flabellina, Moridilla brocki, Bicolor Flabellina, reef crabs, blunt decorated crabs, squat shrimps and banded boxer shrimps emerged. Morays hunted actively and cuttlefish drifted through the beam of torches.
 Big by day. Intricate by night.
Picture
Harlequin Shrimp Pair | Itai Grisaru
Nudibranch with eggs Itai Grisaru Thailand Scuba Diving Liveaboard
Nudibranch Laying Eggs | Itai Grisaru

Day 3 – Similan National Park

Koh Tachai Pinnacle greeted us with explosive fish action. Yellowback, neon, manylined and blue-and-gold fusiliers streamed in the current.
Massive marble groupers and coral groupers rested along granite slopes. Peacock groupers, steephead parrotfish, blue-barred parrotfish and bullethead parrotfish grazed constantly.

Moon wrasse, bird wrasse and pastel green wrasse flashed between coral heads. Batfish hovered in the blue. Blueface angelfish and royal angelfish added vibrant colour.
Hard coral bommies, table corals and giant sea fans framed the scene.
Guest Photographer Itai Grisaru Thailand Scuba Diving Liveaboard
Guest Photographer Extraordinaire Itai Grisaru
Lionfish Thailand Scuba Diving Liveaboard
Lionfish
At Koh Tachai Reef, blacktip reef sharks cruised the shallow reef edge while halgerda tesselata rested near sand patches. Common porcupinefish and yellowdot pufferfish hovered near cracks guarded by giant moray eels. Durban dancing shrimps decorated coral heads.
 
Koh Bon Ridge delivered octopus encounters, Haminoea cymbalum, batfish and oriental sweetlips over powder-blue surgeonfish and lined surgeonfish. Glassfish filled the bay in thick clouds.
 
Blackwater that night brought a completely different universe: purple back squid, lizardfish post-larvae, pyrosomes, tuna larvae, lionfish larvae, butterflyfish post-larvae, triggerfish larvae, coral eggs, female paper nautilus, veligers, crab zoea, tozuma shrimp and even an immortal jellyfish.
Squid Blackwater Diving Thailand Scuba Diving Liveaboard
Squid in Blackwater
larval triggerfish Blackwater Thailand Scuba Diving Liveaboard
Larval Triggerfish in Blackwater
female peper nautilus argonaut blackwater diving Thailand Scuba Diving Liveaboard
Female Paper Nautilus
Immortal jellyfish blackwater diving Thailand Scuba Diving Liveaboard
Immortal Jellyfish in Blackwater
larval lionfish blackwater diving Thailand Scuba Diving Liveaboard
Larval Lionfish in Blackwater

Day 4 – Similan Islands

Three Trees started with garden eels swaying in sandy flats and blue-spotted Kuhls rays feeding nearby. Massive barrel sponges crowned granite boulders.
 
One group spotted a guitar shark — a ray-like shark species combining traits of both families — gliding along the seabed.
 
Schools of yellowback fusiliers, neon fusiliers and scissortail fusiliers mixed with five-lined snappers and yellow saddle goatfish. Great barracuda and dogtooth tuna patrolled deeper edges.
 
Elephant Head Rock delivered blue ribbon eels, adult boxfish, giant trevallies and juvenile clown triggerfish among swim-throughs framed by antler coral and leather coral.
juvenile clown triggerfish Thailand Scuba Diving Liveaboard
Juvenile Clown Triggerfish
ribbon eel itai grisaru Thailand Scuba Diving Liveaboard
Blue Ribbon Eel | Itai Grisaru
West of Eden gave us Thorunna chromodoris, psychedelic batwing seaslug, hairy shrimp and mating octopus pairs. Giant blue-lined pufferfish hovered above the reef alongside copperband butterflyfish and regal angelfish.
batwing sea slug Thailand Scuba Diving Liveaboard
Batwing Sea Slug
hairy shrimp Thailand Scuba Diving Liveaboard
Hairy Shrimp

Day 5 – Koh Lanta National Park

Hin Mueang opened with dramatic walls covered in red soft coral and sea fans. Glossodoris hikuerensis and its eggs decorated the slopes. Trevallies and rainbow runners swept through yellowback and neon fusilier schools.
 
Coral groupers, blacktip groupers and brown marble groupers hid among hard coral ridges. Powder-blue surgeonfish, velvet surgeonfish and Indian mimic surgeonfish crossed the current.
 
Hin Daeng amplified the “big” feeling: batfish, Napoleon wrasse, giant trevallies and dogtooth tuna patrolled the vertical reef. Ghost pipefish hovered delicately near soft corals.
 
Butterflyfish including threadfin butterflyfish, raccoon butterflyfish and Meyer’s butterflyfish added colour, while emperor angelfish and semicircle angelfish patrolled mid-water.
 
Macro remained strong with nudibranchs scattered across the slopes.
 
Blackwater that evening revealed comb jellies hosting isopods and pelagic gastropods drifting through the darkness.
larval crab blackwater diving Thailand Scuba Diving Liveaboard
Larval Crab in Blackwater
gastropod and amphipod blackwater diving Thailand Scuba Diving Liveaboard
Gastropod and Amphipod in Blackwater
Blackwater Diving Entry Thailand Scuba Diving Liveaboard
Ready for Blackwater Diving!
pelagic worm blackwater diving Thailand Scuba Diving Liveaboard
Pelagic Worm in Blackwater
amphipod comb jelly blackwater diving Thailand Scuba Diving Liveaboard
Amphipod on a Comb Jelly

Day 6 – Koh Tarutao National Park

Eight Mile, near the Malaysian border, offered a striking yellow and pink coral-covered pinnacle dotted with sea urchins. Schools of jacks and rainbow runners hovered above.
 
Juvenile semicircle angelfish, juvenile blue-ringed angelfish, juvenile emperor angelfish and regal angelfish contrasted beautifully with the darker reef backdrop.
 

soft coral Thailand Scuba Diving Liveaboard
Vibrant Soft Coral
Stonehenge showcased purple and pink soft corals clinging to sculpted rock formations. A thorny seahorse clung to gorgonians. Yellow-edge moray eels and giant moray eels guarded crevices while tomato anemonefish and masked porcupinefish completed the reef tableau.
 
Koh Sawang at sunset displayed titan triggerfish, giant blue-lined pufferfish, regal angelfish, coral groupers and schools of fusiliers under golden light.
 
Blackwater revealed larval tonguefish, gastropods mating, pelagic worms and drifting crustaceans.
pelagic worm blackwater diving Thailand Scuba Diving Liveaboard
Pelagic Worm in Blackwater
larval tonguefish blackwater diving itai grisaru Thailand Scuba Diving Liveaboard
Larval Tonguefish in Blackwater | Itai Grisaru
mating sea butterfly blackwater diving Thailand Scuba Diving Liveaboard
Mating Sea Butterflies in Blackwater
larval snail blackwater diving Thailand Scuba Diving Liveaboard
Larval Snail in Blackwater
larval shrimp blackwater diving Thailand Scuba Diving Liveaboard
Larval Shrimp in Blackwater

Day 7 – Koh Lanta

Hin Mueang again delivered ghost pipefish, juvenile emperor angelfish, halgerda tesselata and African wrasse.
 
Hin Daeng brought double-spotted queenfish, barracudas, needlefish and more dogtooth tuna, alongside orange-spotted pipefish and lobsters hiding under ledges.​
ghost pipefish itai grisaru Thailand Scuba Diving Liveaboard
Ghost Pipefish | Itai Grisaru
halgerda tessellata nudibranch itai grisaru Thailand Scuba Diving Liveaboard
Halgerda Tessellata Nudibranch | Itai Grisaru
Koh Haa Cathedral provided classic cavern drama: whip coral shrimp, banded sea snake, cleaner pipefish, twin goniobranchus, Cuthona sibogae, Glossodoris hikuerensis, and dark-margin glossodoris with eggs.
 
At Koh Haa Chimney, a banded sea snake guarded the interior cave while Bornella anguilla waited at the exit. Skeleton shrimps and ornate sapsucking slugs clung to soft coral branches.
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The day ended with our traditional BBQ under the stars.
bornella anguilla nudibranch itai grisaru Thailand Scuba Diving Liveaboard
Bornella Anguilla Nudibranch | Itai Grisaru
sap sucking slug itai grisaru Thailand Scuba Diving Liveaboard
Sap Sucking Slug | Itai Grisaru
group photo Thailand Scuba Diving Liveaboard
Happy Group on BBQ Night!

Day 8 – Koh Phi Phi National Park

Koh Bida Nok welcomed us with blacktip reef sharks cruising the reef. Tiger-tail seahorses and ghost pipefish clung to soft corals. Schools of yellow-lined snappers and yellowback fusiliers swirled around healthy hard coral formations.

Eagle Ray at Shark Point | Video Taken by Dive Guide Vélika

At Shark Point, a not-so-shy eagle ray joined our final dive, swimming alongside schools of yellowback fusiliers, five-lined snappers, yellowtail and chevron barracudas. Cadlinella ornatissima rested quietly on the reef.
happy divers Thailand scuba diving Liveaboard
Happy Divers
cadlinella ornatissima nudibranch itai grisaru Thailand scuba diving Liveaboard
Cadlinella Ornatissima Nudibranch | Itai Grisaru
From pelagic mantas and hunting trevallies to delicate nudibranchs and larval life, this trip perfectly balanced the immense and the microscopic.
 
Another North to South Andaman journey comes to an end — and once again, the Smiling Seahorse delivered both spectacle and subtlety in equal measure.
 
Until next time.
 
Photo by Franck Fogarolo & Itai Grisaru
Koh Haa cadlinella ornatissima nudibranch itai grisaru Thailand scuba diving Liveaboard
A View of Koh Haa
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