Similan Islands & Surin Islands scuba diving

A limestone pinnacle east of Koh Surin Nua, ringed by smaller pinnacles and covered in vivid soft coral. Seahorses and ghost pipefish hide in the coral while big schools of pelagics circle above, and it is one of the best chances in Thailand of meeting a whale shark.

A limestone ridge running west off Koh Bon, stepping down from the shallows to around 40 m with a dramatic wall alongside. Often called the best place in the region to find manta rays. Currents vary from dive to dive, so it suits confident divers.

Granite boulders rise to 12 m from sand at around 30 m, with a second, smaller pinnacle across the sand. The current here can be the strongest in the area, which is what brings in the plankton, mantas and the odd whale shark, especially from February to April. Usually dived as a drift.

A gentle reef sloping from 5-10 m down to sand at 20-30 m, covered in hard coral and known as Leopard Shark Reef. An easy, relaxed dive and a nice contrast to the pinnacle next door. The island is closed to visitors, but the dive sites around it are open.

Giant granite boulders 1 km southwest of Island 8, cut by swim-throughs, channels and gorges. Currents are strong and change quickly, and the boulders double as shelter while schools of fish and passing pelagics go by. Often rated the most spectacular site in the Similans.

Huge granite boulders at the northwest tip of Island 9, stacked into arches and passages including an iconic swim-through at 18-20 m. Soft corals and sea fans cover the rocks, big schools of fusiliers and snappers ride the current, and whitetip reef sharks rest on the deeper sand.

Granite boulders, channels and a steep wall covered in coral gardens on the west side of Island 7. Turtles feed in the shallows and big pelagics pass in the blue, so both macro and wide-angle photographers have plenty to shoot.

A slow, gentle drift along one of the healthiest hard and soft coral reefs in the Similans, on the east side of Island 7. Big clusters of staghorn coral hide ghost pipefish, ribbon eels and nudibranchs, and blacktip and leopard sharks show up on good days.

Three huge granite boulders at around 22 m sit on a sandy slope that drops past 30 m, with a shallow reef from 7-15 m that is perfect for drifting. Rich coral growth, barracuda and turtles, plus plenty of macro for photographers.

Massive granite boulders form swim-throughs and canyons from 10 m down to 40 m. The profile is so flexible that guides can keep it shallow and easy for newer divers or take experienced divers deeper.

A tuna trawler sunk by the Thai authorities in 2003 at the foot of the Hideaway Bay slope, lying on its side at 28-35 m. Schools of snapper, trevally and batfish hang around the hull and critters hide inside. Its depth calls for good buoyancy and air management, so it is for Advanced divers.

A gentle, sheltered reef slope at the southern tip of Koh Surin Tai, ideal for first dives and skill practice. Coral gardens are home to turtles, schools of reef fish, moray eels and blue-spotted stingrays, with plenty of macro too.