Thailand’s Andaman Sea and Gulf of Thailand host some of the most diverse and accessible dive sites in Asia. Whether you’re chasing whale sharks, exploring granite pinnacles, or gliding past coral gardens, the variety is unmatched. These five locations represent the best of Thailand’s underwater world, and together they make a compelling case for why the country remains one of the world’s favourite diving destinations.
1. Richelieu Rock – The Icon of the Andaman
Tucked near the Surin Islands, Richelieu Rock is Thailand’s most famous dive site. Covered in vibrant purple soft corals, it attracts everything from ghost pipefish and seahorses to swirling schools of barracuda. Between February and April, whale shark sightings are common. The site’s remote position means it’s only accessible by liveaboard, adding to its pristine allure.
2. Koh Bon – Manta Encounters in Motion
Part of the Similan Islands National Park, Koh Bon is Thailand’s manta ray hotspot. The reef slopes into a deep ridge where cleaning stations draw these graceful giants, often circling just metres away. The surrounding coral gardens are equally rich with anthias, nudibranchs, and moray eels.
3. Hin Daeng and Hin Muang – Deepwater Drama
Located south of Koh Lanta, these twin pinnacles rise from over 60 metres of open water. Draped in red and purple soft corals, Hin Daeng and Hin Muang are known for big pelagics, including whale sharks and mantas. Strong currents and deep profiles make them ideal for experienced divers seeking adrenaline and colour in equal measure.
4. Sail Rock – Gulf of Thailand’s Hidden Gem
In the Gulf, between Koh Samui and Koh Tao, Sail Rock is famous for its vertical “chimney” swim-through and teeming marine life. Schools of snapper, fusiliers, and giant groupers fill the blue, while whale sharks occasionally cruise by. It’s easily reached from Koh Phangan and makes an excellent inclusion for divers travelling the eastern islands.
5. Elephant Head Rock – The Granite Maze
Within the Similan Islands, Elephant Head Rock offers a playground of granite arches, tunnels, and swim-throughs that feel both dramatic and intimate. The site draws white-tip reef sharks, trevallies, and Napoleon wrasse, along with a backdrop of stunning visibility and vibrant soft corals. Its cinematic topography makes it a favourite among underwater photographers.
Thailand: A Year-Round Dive Paradise
With warm tropical waters, professional operators, and a mix of beginner-friendly reefs and advanced drift dives, Thailand is as diverse as it is beautiful. From the coral plateaus of the Similans to the deep-water pinnacles off Koh Lanta, each region offers something unique.
Whether you join a liveaboard in the Andaman or enjoy day trips from Koh Tao, Thailand’s underwater world continues to deliver exactly what divers come for: adventure, colour, and the sense of discovering a living, breathing ocean.
