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Trip report | Marine Biology cruise with Whale Shark specialist | 20th - 27th March 2026

31/3/2026

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.

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 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.

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.

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.

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.

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.

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Trip report | 10th - 18th March 2026 | Mergui Archipelago & Burma Banks

20/3/2026

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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

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

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.

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

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.

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

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.

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.

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.

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

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.

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.

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

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Trip report | 1st – 8th March 2026 | South & North Andaman Expedition

13/3/2026

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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

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

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

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

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

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

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.

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

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

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Trip report, 20th–27th February 2026, Thailand North and South Andaman Excursion

2/3/2026

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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

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

Turtle

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

"The Gang" Hunting at Richelieu Rock

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

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.

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

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

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

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 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

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.

The day ended with our traditional BBQ under the stars.

Bornella Anguilla Nudibranch | Itai Grisaru

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

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

A View of Koh Haa

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Trip report | Marine Biology cruise with Whale Shark specialist | 20th - 27th March 2026

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

​Day 2 – Surin National Park & Richelieu Rock

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

​Day 4 – Similan Islands & Crossing

​Day 5 – Hin Daeng & Hin Mueang

​Day 6 – Koh Tarutao National Park

​Day 7 – Koh Lanta National Park

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

​Day 8 – Koh Phi Phi & Final Dive

Trip report | 10th - 18th March 2026 | Mergui Archipelago & Burma Banks

Day 1 – From Ranong to the Mergui Archipelago​

Day 2 – High Rock​

Day 3 & 4 – Black Rock

Day 5 – Three Islets & Crossing to the Burma Banks

Day 6 – Burma Banks

Day 7 – Burma Banks ​

Day 8 – Seafan Forest & Western Rocky

Manta Ray at Black Rock | Camille Rovillain

Day 9 – Dendro’s Peak & Farewell ​

Trip report | 1st – 8th March 2026 | South & North Andaman Expedition

Day 1 – From Phuket to Koh Phi Phi National Park​

Ready To Dive | Vélika Marquis

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

Day 3 – Koh Lanta National Park​

Day 4 – Similan National Park​

Day 5 – Similan National Park​

Day 6 – Similan National Park​

Day 7 – Surin National Park​

Day 8 – Return to Ranong​

The Richelieu Rock "Gang" | Udi Nehab

Trip report, 20th–27th February 2026, Thailand North and South Andaman Excursion

Day 1 – From Ranong to Surin National Park

Day 2 – Surin National Park

Day 3 – Similan National Park

Day 4 – Similan Islands

Day 5 – Koh Lanta National Park

Day 6 – Koh Tarutao National Park

Day 7 – Koh Lanta

Day 8 – Koh Phi Phi National Park

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

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

Day 2 – Surin National Park & Richelieu Rock

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

Day 4 – Similan Islands & Crossing

Day 5 – Hin Daeng & Hin Mueang

Day 6 – Koh Tarutao National Park

Day 7 – Koh Lanta National Park

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

Day 8 – Koh Phi Phi & Final Dive

Day 1 – From Ranong to the Mergui Archipelago

Day 2 – High Rock

Day 7 – Burma Banks

Day 9 – Dendro’s Peak & Farewell

Day 1 – From Phuket to Koh Phi Phi National Park

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

Day 3 – Koh Lanta National Park

Day 4 – Similan National Park

Day 5 – Similan National Park

Day 6 – Similan National Park

Day 7 – Surin National Park

Day 8 – Return to Ranong