Trip Report: Thailand South to North Andaman Liveaboard, 15–22 January 2026

Trip Report: Thailand South to North Andaman Liveaboard, 15–22 January 2026

Turtle Koh Tachai Andaman Sea Thailand Liveaboard
This 8-day south-to-north Andaman liveaboard charter offered an exceptional cross-section of Thailand’s Andaman Sea diving. From calm lagoons and dramatic southern pinnacles to the fish-rich northern marine parks and legendary Richelieu Rock, the trip combined pelagic action, rare macro life, vibrant coral reefs and relaxed liveaboard living. Calm seas and good visibility throughout allowed us to fully enjoy each site with our private group of US guests.
hard coral and butterflyfish, Andaman Sea liveaboard
Hard coral and butterflyfish
Barrel sponge and bannerfish Andaman Sea Thailand Liveaboard
Barrel sponge and bannerfish
Day 1 – Phuket to Koh Haa Lagoon
We welcomed our guests aboard in Phuket before departing toward Koh Haa Lagoon. The afternoon was spent settling in, assembling dive gear, and enjoying the first sunset at sea as we cruised south. Anticipation built for the check dive scheduled for the following morning in the calm, protected lagoon.
psychedelic batwing sea slug, Andaman Sea liveaborad
Psychedelic batwing sea slug
pygmy pipehorse, which is a type of small marine fish closely related to seahorses and pipefish.
Pygmy pipehorse, which is a type of small marine fish closely related to seahorses and pipefish.
Day 2 – Koh Haa, Hin Daeng & Hin Muang
Our check dive at Koh Haa Lagoon provided ideal conditions to ease into Andaman diving. A hawksbill turtle cruised past the reef while a blacktip reef shark patrolled the edge of the lagoon. Moray eels peered from coral heads, including a memorable sighting of a moray eel swimming freely across the sand. African pompano and longnose emperors passed through the blue, while oriental and harlequin sweetlips hovered near the reef. Macro highlights included a black cat headshield slug and a delicate Fabalina nudibranch. Wrasses, parrotfish, butterflyfish, angelfish, surgeonfish and clouds of damselfish filled the shallow reef.
The second dive at Hin Daeng delivered immediate big-fish energy. Schools of batfish glided along the drop-off, surrounded by bluefin trevallies, giant trevallies, rainbow runners and barracuda. Potato groupers rested on ledges, while redtooth triggerfish, juvenile angelfish and schooling bannerfish animated the reef. Honeycomb and snowflake moray eels hid among soft corals, while ghost pipefish, spotted Hypselodoris, anemone clownfish and anemone crabs rewarded careful observation.
At Hin Muang, the third dive featured strong currents and excellent fish life. Dogtooth tuna and golden trevallies cruised past in the blue, joined by milkfish and schools of naked fusiliers. Batfish hovered near the pinnacle as glassfish swirled tightly around coral outcrops, constantly harassed by hunting jacks. Coral groupers, a shy lobster, multiple ghost pipefish and a striking juvenile emperor angelfish completed the scene.
Our night dive revealed a different side of the reef. Hunting moray eels, including bartail and snowflake morays, moved actively across the coral. A resting hawksbill turtle, yellow boxfish and a cruising barracuda were highlights, while the reef came alive with macro life such as tiger cowries, Mauritia arabica immanis, Willey’s Halgerda, bicolor Fabelina, Jebb’s flatworm and sapsucking slugs.
tiger cowrie, liveabord Thailand and Myanmar
Tiger cowrie
Clownfish, anemon and soft coral, Thailand and Myanmar liveaboard
Clownfish in their anemone
Potato grouper in Hin Muang, Koh Lanta National park
Potato grouper in Hin Muang, Koh Lanta National park
Big eye trevally Richelieu Rock, Andaman Sea liveaboard
Big eye trevally schooling
Day 3 – 8 Mile Rock, Stonehenge & Koh Sawang
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Two morning dives at 8 Mile Rock delivered classic Andaman schooling action. Great barracudas cruised above the reef while schools of yellow snappers, bigeye trevallies and bluefin trevallies moved in unison. Red-bar anthias coloured the reef, joined by marbled groupers, fimbriated moray eels and ghost pipefish. Allied cowries and Chromodoris nudibranchs added macro interest among hard corals, sea fans and sponges.
The third dive at Stonehenge showcased its famous soft-coral formations in full colour. Layers of red, orange and purple soft corals covered the structures, sheltering flounders, tomato clownfish and a black-gill Phestilla nudibranch. A Kuhl’s stingray rested on the sand while a massive sea snake moved calmly through the reef. Schools of snappers, wrasses, parrotfish and fusiliers filled the water column.
Our final dive of the day at Koh Sawang focused on critter life. A huge spearer mantis shrimp was the standout, accompanied by yellow boxfish, porcupinefish, rabbitfish, whip coral shrimp and squat shrimp. Bluefin trevallies continued to patrol the deeper sections of the site.
Male Bartels' Dragonet (Synchiropus bartelsi). This species is native to the southwest Pacific Ocean, found from Japan to Australia, and eastwards to the Marshall Islands and Fiji.
Male Bartels’ Dragonet (Synchiropus bartelsi).
spearing mantis shrimp, Andaman Sea liveaboard
Spearing mantis shrimp
Orangutang crab, Andaman Sea Liveaboard
Orangutang crab
Day 4 – Hin Muang, Hin Daeng & Koh Haa Cathedral
Returning south for one final day before heading north, Hin Muang once again delivered strong action with ghost pipefish, rainbow runners, batfish, tuna and great barracudas. A dramatic moment unfolded as predatory fish hunted inside a dense glassfish bowl. Spiny lobsters and redtooth triggerfish were common along the reef.
At Hin Daeng, ornate ghost pipefish were spotted among soft corals while yellowtail and dogtooth tuna hunted glassfish in the blue. Schools of batfish, oriental sweetlips, milkfish and juvenile emperor angelfish moved across the drop-off, accompanied by honeycomb morays and redtooth triggerfish.
The third dive at Koh Haa Cathedral featured impressive swim-throughs and beams of light cutting through the cave. Giant and snowflake moray eels hid among the rocks, while potato groupers rested near the entrance. Bluefin trevallies, schools of yellow snappers, a passing reef shark and Spanish mackerel cruised by. Macro highlights included Halgerda tessellata, baby boxfish and sea cucumbers scattered across the reef.
That evening, we began our transit north toward the Similan Marine Park.
banded pipefish, Andaman Sea liveaboard
Banded pipefish
Cute baby seahorse on the coral reef, liveaboard Thailand and Myanmar
Cute baby seahorse on the coral reef
Day 5 – Similan Islands & Koh Bon
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At Sharkfin Reef, hawksbill turtles cruised along the granite boulders, accompanied by longnose emperors, bluefin trevallies and schools of neon and lunar fusiliers. Flatworms, wrasses, parrotfish, butterflyfish and surgeonfish filled the reef.
West of Eden (Similan Island #7) offered a lush reefscape. Giant moray eels, peacock mantis shrimp, brown marbled groupers and baby honeycomb morays were spotted alongside red fire gobies, flasher wrasse, cornetfish, starry dragonets and African sand wrasse. Two turtles passed slowly through the reef while schools of fusiliers streamed overhead.
At Three Trees (Similan Island #9), bird wrasses, clown triggerfish, big jobfish and a Napoleon wrasse dominated the dive, joined by an eagle ray gliding through the blue and several cornetfish cruising between bommies.
Our sunset dive at Koh Bon Ridge and Reef brought giant trevallies hunting among glassfish, massive schools of emperors, fusiliers, Andaman sweetlips, angelfish and coral groupers as the light faded.
Juvenile clown triggerfish, Andaman Sea Liveaboard
Juvenile clown triggerfish
spearing mantis shrimp, liveaboard Thailand and Myanmar
Day octopus
Harlequin shrimps, liveaboard Thailand and Myanmar
Harlequin shrimps
Day 6 – Koh Bon, Koh Tachai & Night Dive
Morning dives at Koh Bon Pinnacle and West Ridge were packed with schooling fish. Batfish, barracudas, bluefin trevallies, giant trevallies, bannerfish and butterflyfish surrounded the pinnacle, joined by coral groupers, lionfish, emperors and double-spotted queenfish. Yellow goatfish hunted alongside trevallies, while moray eels and tuna patrolled the reef edges.
After cruising north, we reached Koh Tachai Plateau, where schools of barracuda, GTs, bluefin trevallies and dogtooth tuna dominated the dive. A hawksbill turtle passed by, followed by a large Jenkins whipray. Juvenile and adult clown triggerfish, royal angelfish, brown marbled groupers and batfish completed the scene.
The night dive at Koh Tachai Reef was a standout. Five blacktip reef sharks remained with the divers for 30–40 minutes, while checkered, mangrove and red snappers actively hunted. Fusiliers, barracuda, lionfish and another turtle encounter made for an unforgettable evening dive.
blacktip reef sharks, liveaboard Thailand and Myanmar
Blacktip reef sharksc
several blacktip reef shark in thailand
5 blacktip stayed with us for the delight of all divers
We also went on a Blackwater dive that night and it didnt disappoint with its fair share of cephalopods, crustaceans and juvenile fish!
Get ready for blackwater diving, Andaman Sea Thailand
Get ready for blackwater diving
Hyperiid amphipod, liveaboard Thailand and Myanmar
Hyperiid amphipod hitching a ride
Baby squid on blackwater dive, Andaman liveaboard
Baby squid on blackwater dive
Larval anemone on blackwater dive, Andaman Sea Thailand
Larval anemone on blackwater dive
gastropod on blackwater dive, Andaman Sea liveaboard
Gastropod on blackwater dive
Baby lobster on blackwater dive, Andaman Sea liveaboard
Baby lobster on blackwater dive
Mating sea angels, Andaman Sea Thailand
Mating sea angels
Days 7 & 8 – Richelieu Rock
A full two days of diving at Richelieu Rock delivered everything the site is famous for. The “gang” of giant trevallies, longnose emperors and rainbow runners hunted together through clouds of glassfish and fusiliers. Schools of barracuda, amberjacks and batfish circled the pinnacles, while coral groupers and sweetlips occupied the reef.
Macro life was exceptional: thorny seahorses, octopus, jawfish, harlequin shrimp, cleaner pipefish, orange-spotted pipefish, ornate sapsucking slugs, Dermatobranchus and Nendronotis species, tiger egg cowries, spearer mantis shrimp and juvenile clown triggerfish were all recorded. Additional sightings included juvenile blue triggerfish and ridged dermatobranchs.
The final two dives on Day 8 brought more jawfish, thorny seahorses, octopus, schools of barracuda and batfish, peacock-tail shrimp and mole cowries—an ideal conclusion to the trip.
After the last dive, we cruised north to Ranong, where guests disembarked, bringing this South-to-North Andaman journey to a close.
Happy team on the MV Smiling Seahorse
Happy team on the MV Smiling Seahorse
Guess what marine creature our guest saw...
Guess what marine creature our guest saw…
A smile on all faces! That's our reward!!!! Andaman Sea liveaboard
A smile on all faces! That’s our reward!!!!

2 Responses

  1. This was an experience we will never forget! Tons of sea action and wonderful memories made on the Smiling Seahorse. The staff was over the top with education, Thailand Cuisine and laughter that will be in our minds for eternity. Thank you to all!

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