Dive into the mysterious depths of Thailand’s Andaman Sea, where the night reveals an otherworldly world teeming with bizarre and beautiful creatures. On our latest adventure aboard the MV Smiling Seahorse, we set off on a special journey through the North Thai Andaman Sea, exploring the iconic dive sites of Surin and Similan National Parks, and diving into the unique world of blackwater diving on every divable night.
Our divers hailed from all over the world—France, Switzerland, the USA, and Germany—and were joined by special guest, professional underwater photographer Alex Tyrrell. Alex brought his expertise to the trip, sharing valuable tips on how to get the best shots, especially on blackwater dives and sharing with us some unforgettable moments.
What is Blackwater Diving?
Blackwater diving is a thrilling night dive that takes place far from reefs and shore, in the open ocean. Divers descend along a suspended line with lights, attracting deep-sea critters that migrate to the surface at night. This unparalleled experience offers a glimpse into the bizarre, larval-stage creatures and deep-sea life that thrive in the darkness, seldom encountered by divers.
Day 1 : Diving in the surin islands
We began our journey in the pristine waters of the Surin National Park with dives showcasing the vibrant marine life of this protected area. The first dive at Koh Chi served as a check dive, where we encountered schools of yellow-lined snappers and yellow fusiliers, and a graceful hawksbill turtle joined us for a swim, reminding us of the beauty of this marine sanctuary.
For the second dive at Yellow Rock, we enjoyed sightings of blue-spotted stingrays, oriental and black-spotted sweetlips, schools of yellowtail barracuda and yellow pompanos, along with flabellinas, giant moray eels, and blue-spotted pufferfish.
At Ao Pakkard during the third dive, we were treated to razor wrasse, a school of baby blackfin barracuda, imposter sabertooth blennies, and striped eel catfish. After a night dive on the reef, back at Ao Pakkard, we were ready for offshore blackwater adventures on subsequent nights. Jenkins stingrays, xenocrabs, hermite crabs, coral crabs, cleaning shrimps, and blue-spotted stingrays provided a magical underwater experience.
Day 2 : Richelieu Rock
Richelieu Rock is one of the most iconic dive sites in the world, and it certainly lived up to its reputation. With perfect visibility, we watched emperors and giant trevallies hunting in the blue alongside schools of jacks, neon fusiliers, and pickhandle barracuda. The reef dazzled with macro life, including cleaner pipefish, porcelain crabs, nudibranchs, and blue dragons. A rare sighting of a white frogfish, juvenile oriental sweetlips, and a massive potato grouper made the dive even more spectacular. Alex captured one of his most remarkable moments of the trip here, photographing pharaoh cuttlefish mating and laying eggs—a fascinating natural spectacle. Unfortunately the wind picked up and we couldn’t do our first blackwater dive planned that day and had to find shelter in Surin islands for the night.
Our third day took us to the Similan Islands, starting with two dives at Koh Tachai. The waters were clear, and the visibility was perfect as we swam alongside schools of bigeye trevallies, yellowback fusiliers, and pickhandle barracudas.
We also encountered potato groupers, batfish, and a rare sea moth. Our third dive at Koh Bon Pinnacle was breathtaking, with massive schools of neon fusiliers and batfish. The afternoon dive took us to the ridge of Koh Bon, where we found sweetlips, mantis shrimp, and the Maldivian sponge snail
We finally could jump into our first blackwater dive that night, and what a treat! We spotted many interesting post-larval critters such as octopuses, lobsters, squid, and flying gurnards drift past our lights drifting past our lights.
Baby octopus
Sea Butterfly
Flying gurnard
Baby crab
Day 4 : More of the Similan National Park
The day began with a dive at Koh Bon Pinnacle and North Ridge, where the visibility was beautiful, revealing the vibrant underwater life. Divers encountered massive schools of yellow back and neon fusiliers, alongside groupers and sweetlips at the North Ridge. Adding to the spectacle were bearded scorpionfish, colorful Moorish idols, and a variety of angelfish and butterflyfish, including raccoon and threadfin butterflyfish.
The second dive took place at Three Trees, located on Island number 9 of the Similan Islands. With crystal-clear waters and striking bommies and boulders, this site was teeming with marine life. Highlights included blue spotted stingrays, garden eels, and potato groupers. Additionally, divers admired schools of Bengal snappers, lunar fusiliers, and gold-saddle rabbitfish, weaving through the coral formations.
In the afternoon, the team prepared for two more blackwater dives off the back of Island 8 due to still strong eastern winds, which made open ocean conditions less favorable than usual. Despite this, the dives were successful with only about 70 meters of water under the boat, we met post-larval creatures like flying gurnards, butterflyfish, mantis shrimp, snake eels, and flounders made for an enchanting and surreal experience
There was so much life in the water!
including this pretty octopus!
this looks like a young cobia!
Ever wandered what Mantis shrimp look like before they settle on the reef…
this is an eel but not sure which type (could be a moray, ribbon eel or other species).
this is a Siphonophore, they are pretty but dont go kiss them, they sting!
Day 5 : Similan National Park
The morning commenced with a dive at West of Eden, a vibrant site where Simon spotted a rare sea moth and many pretty psychedelic sea slugs!
More common but still exciting where sightings of giant trevallies, peacock mantis shrimps, and colourful nudibranchs, while a small hawksbill turtle leisurely swam by. Adding to the scene were blue-lined groupers, adorned wrasses, and a myriad of anemonefish darting among the corals.
Potato grouper pausing with snappers in front of a giant seafan
Anemonefish, a signature Andaman Sea inhabitant
The day concluded with two more blackwater dives off the back of Island . Despite continued strong eastern winds, these dives offered mesmerizing encounters with pipefish, cusk eels, longarm octopuses, big squids, larval lionfish, and moray eels, showcasing the captivating diversity of the nocturnal ocean realm.
This is a rare type of Cusk-eel larva. Which so far hasn’t been spotted by any of the photogrpahers who regularily post in blackwater photo group!
Larvacean – Pelagic Tunicate – Appendicularia
Pipefish
plenty of photogenic squids around
Octopus
Day 6 : Koh Bon Pinnacle and Ridge
We concluded our trip with two dives at Koh Bon Pinnacle and Ridge, exploring hard coral gardens and enjoying incredible visibility. Schools of batfish and tuna filled the blue, while nudibranchs and reef fish added vibrant colors to this final underwater adventure.
This trip was a perfect blend of vibrant reefs, fascinating macro life, and the thrilling mystery of blackwater diving.
Our divers captured stunning photos of their underwater experiences, some of which you can see in our albumhere. We look forward to welcoming more divers aboard for our next adventure and more blackwater diving in the Andaman Sea!
