After check-in and Thai immigration formalities, we boarded the boat and headed across the Pakchan River to Kawthung for Burmese immigration. Passports stamped, gear prepped, smiles wide — our expedition began.
Day 2 — Mergui’s First Wonders
At Three Islets, the Submarine site gave us a lovely first encounter with a bamboo shark tucked into a rocky crack, and a turtle drifting lazily overhead. We found orange-spotted pipefish and the elegant nudibranch Chromodoris rufomarginata on the sandy slope. Shark Cave was buzzing with life; the entire cave shimmered with sweepers, and outside the entrance clouds of fusiliers pulsed in the current. Sergeant majors were fiercely defending their eggs while wrasses, angelfish, butterflyfish, and triggerfish opportunistically picked at any moment of distraction. Wahoos streaked through the blue, accompanied by a great barracuda, golden trevallies, and even a giant bicolour parrotfish. Square continued the spectacle with more tigertail seahorses, a giant moray, and well-hidden bearded scorpionfish.
Our night dive around Square and Shark Cave was a treasure hunt of nocturnal critters. Five tigertail seahorses showed up, along with sponge spider crabs, decorated crabs, Godiva quadricolor nudibranchs, and sleepy pufferfish wedged among the corals. Soldierfish and cardinalfish hovered in the glow of our torches while hinge-beak shrimp and banded cleaner shrimp darted from rock to rock.
Day 3 — Twin Islands & Blackwater Magic
South Twin Reef delivered even more action with partner shrimps and peacock mantis shrimps scurrying along the sandy patches. Juvenile triggerfish flicked between coral heads while gold-saddle rabbitfish fed in tight groups. Four dogtooth tunas shot past in formation. Blue dragon nudibranchs were scattered everywhere, and the reef was alive with lined and stripe-bristletooth surgeonfish. A Jenkins ray rested on the sand beside a blue-spotted stingray, while yellow-edge and giant morays watched from shaded holes. An octopus shifted colours as we approached, and juvenile oriental sweetlips wiggled in their rhythmic dance. We ended the dive drifting over beautiful table corals and elegant funnel corals.
Day 4 — Sea Fan Forest & Western Rocky
At Western Rocky, we entered the famous cave with octopus and cuttlefish patrolling the entrance. Coral-banded shrimp and red reef crabs clung to the walls, and we spotted a delicate wentletrap snail and a striking Maldivian sponge snail on the sandy floor. Blue dragon nudibranchs added flashes of purple and white as we continued along the reef, passing bannerfish, goatfish, snappers, and butterflyfish enjoying the current.
Our sunset dive around the Western Rocky islets unfolded beautifully as clouds of fusiliers, sergeant majors, and damsels swirled around us. Harlequin shrimps crept delicately over the rocks, and more Maldivian sponge snails dotted the reef. White-tongue trevallies chased schools of baitfish, accompanied by scribbled filefish, pyjama surgeonfish, rainbow runners, golden trevallies, and a pack of blacktail barracudas. At one point, two giant morays squeezed together inside the same hole, seemingly unbothered by each other's presence.
Day 5 — Mantas, Currents & Forest Walls
The afternoon dives at Sea Fan Forest were equally memorable. Fusiliers filled every corner of the reef, and another tigertail seahorse clung to a sea fan. A pharaoh cuttlefish hovered confidently before drifting away into the blue. Pickhandle barracudas and golden trevallies patrolled the sandy patches while batfish, moorish idols, and titan triggerfish appeared throughout the site. A large tiger cowrie, several anthias, wrasses, butterflyfish, and damsels added detail to the coral scene. More octopus and a well-camouflaged stonefish ended the day.
That night’s blackwater dive was exceptionally special, featuring a female paper nautilus drifting like a delicate origami shell. Larval wrasses and tiny fish sheltering inside jellyfish floated through the dark, and we found many larval triggerfish and fish living inside salps — a perfect finale to the drifting night.
Day 6 — Into Thailand: Surin & Richelieu Rock
What Makes Richelieu Rock Famous?
- A horseshoe-shaped pinnacle covered in purple and pink soft corals
- Massive schools of trevallies, barracudas, and snappers
- Incredible macro life: ghost pipefish, harlequin shrimps, tiger eggs cowries
- Historically known for whale shark sightings
- Named after Admiral Andreas du Plessis de Richelieu, a Danish officer who served as Commander-in-Chief of the Royal Siamese Navy — not the French cardinal, despite the popular legend
Our first dive at Richelieu Rock was enchanting. Dense schools of glassfish wrapped the entire reef in a shimmering veil. Longnose emperors worked in tight groups, flashing brilliant colours as they hunted, while giant trevallies, bluefins, white-tongue trevallies, and bigeyes patrolled the edges. Batfish hovered calmly around the cleaning stations, and titan triggerfish bulldozed their way along the bottom. Octopus displayed quick colour changes, and huge potato groupers watched us from between the cracks. White-eye, zebra, and yellow-edge moray eels peeked from the crevices, and tiny tiger-egg cowries clung to sea fans. Nudibranchs including chromodoris and flabellina added delicate splashes of colour while bannerfish, wrasses, dartfish, anthias, and butterflyfish decorated every corner of the reef.
Our night dive at Surin South (Ao Pakkard) offered a different perspective. Giant red crabs prowled the sandy areas, Durban dancing shrimps and marble shrimps flickered under our torches, and boxer-banded shrimps waved their oversized claws. Parrotfish, surgeonfish, and pufferfish were already tucked into their nighttime hideouts, while barracudas sliced through the dark hunting yellowback fusiliers.
Day 7 — Richelieu, Similans & Koh Tachai
Similan National Park Highlights
- Famous for giant granite boulders and white-sand beaches
- Excellent visibility and vivid blue water
- Frequent encounters with manta rays, whale sharks, and giant trevallies
- Beautiful coral gardens with sea fans, hard corals, and soft coral patches
Our third dive at Koh Tachai brought us into the energetic mix this site is known for. Bluefin trevallies and chevron barracudas hunted in packs while giant trevallies and dogtooth tunas patrolled the deeper zones. Marble groupers rested on the bommies while longfin bannerfish, unicorn surgeonfish, angelfish, and massive swarms of fusiliers filled the reef. Lobsters and snappers hid among the corals, and batfish drifted by in lazy groups.
At Koh Bon, we explored the ridge and bay where hard corals glowed beautifully in the afternoon light. A baby blacktip shark cruised the shallows while an octopus hid in a coral crack. Maldivian sponge snails dotted the reef. The dive ended with colourful scenes full of wrasses, goatfish, butterflyfish, damsels, and scorpionfish, with the occasional wahoo and giant moray cruising through the dusk.
Day 8 — Racha Noi to Finish
At Manta Reef, we found Glossodoris cincta, a snowflake moray, and several seal-face pufferfish drifting over the sandy bottom. Garden eels swayed in the light current as blue-spotted rays glided past. Butterflyfish, damsels, and a bearded scorpionfish rounded out the dive while yellowback fusiliers danced above in glittering swirls.
A Perfect Journey Across Two Countries
Thank you to our wonderful divers from Israel for sharing this week with us and their wonderful photos to illustrate this blogpost!
See you soon for another adventure with the MV Smiling Seahorse! 🐟💙

























































RSS Feed
