From the beginner-friendly reefs of Koh Tao (which certifies more divers than almost anywhere on Earth) to the world-class Similan Islands, Thailand's underwater scene is spectacular and affordable. Here's where to dive, snorkel and take your first breaths underwater.
When to dive in Thailand
The Andaman side (Similans, Phi Phi, Koh Lanta) is best from November to April; the Gulf side (Koh Tao, Koh Samui, Koh Phangan) dives well most of the year with a sweet spot from March to September. Whale sharks are a lucky possibility at pinnacle sites in the shoulder seasons.
Best destinations
Top experiences
Phuket
- Similan Islands day trip — World-class snorkelling and diving on powder-white reefs (Nov-Apr).
- Coral & Racha Island snorkelling — Clear shallow reefs a short speedboat hop offshore.
Koh Phi Phi
- Bamboo Island snorkelling — Powder sand and shallow reefs full of fish.
- Dive with reef sharks — Blacktip reef sharks and turtles at Bida Nok and Shark Point.
- Loh Samah Bay snorkel — Colourful coral and fish in a sheltered turquoise bay.
Koh Lanta
- Koh Rok & Koh Haa — Some of the Andaman's clearest snorkelling and diving water.
- Hin Daeng & Hin Muang diving — Deep pinnacle dives famous for manta rays and whale sharks.
Koh Samui
- Koh Tao & Nang Yuan day trip — Speedboat snorkelling at the gulf's clearest reefs.
Koh Phangan
- Koh Ma snorkelling — Swim the sandbar reef at Mae Haad on the northwest tip.
Koh Tao
- PADI diving course — Koh Tao certifies more divers than almost anywhere on earth - warm, cheap, easy.
- Koh Nang Yuan — The iconic triple-island sandbar and its viewpoint.
- Shark Bay — Snorkel with harmless blacktip reef sharks off the beach.
- Mango Bay & Aow Leuk — Sheltered coral coves ideal for easy snorkelling.
- Chumphon Pinnacle dive — The area's top site — granite spires, groupers and whale-shark season.
- Aow Leuk & Hin Wong bays — Snorkel straight off the beach in calm, coral-rich coves.
Railay
- Four Islands tour — Longtail hop to Koh Poda, Chicken Island and the Tup Island sandbar.
- Hong Islands day trip — Emerald lagoon enclosed by cliffs, plus snorkelling around the surrounding islets.
Khao Lak
- Similan Islands day trip — Speedboat to granite islands with some of Thailand's clearest water and reefs.
- Richelieu Rock liveaboard — Multi-day dive trips to a pinnacle famous for whale sharks and seahorses.
- Surin Islands — Remote national park reefs and a Moken sea-nomad village, by speedboat.
Similan Islands
- Koh Payu reefs — Shallow hard corals, reef fish and turtles close to the surface.
- Elephant Head Rock — Signature dive through granite swim-throughs and boulder canyons.
- Christmas Point — Dramatic arches and boulders with soft corals and schooling fish.
Koh Jum
- Koh Phi Phi day trip — Longtail or speedboat trip to Phi Phi's bays and snorkelling spots.
- Koh Dam & Hong Islands — Island-hopping to nearby sandbars, lagoons and clear-water reefs.
Koh Lipe
- Longtail snorkelling trip — Hop between Koh Rawi, Koh Yang, Koh Hin Ngam and Koh Usen reefs.
- Stonehenge & Eight Mile Rock — Soft-coral pinnacles and deeper dives among the best in the far south.
- PADI Open Water course — Calm, clear bays make Lipe a relaxed place to learn to dive.
Koh Ngai
- House-reef snorkelling — Swim out from the beach to coral, parrotfish and giant clams.
- Four-island tour — Longtail day to Koh Chueak, Koh Waen, Emerald Cave and Koh Kradan.
- Koh Chueak & Koh Waen — Limestone rocks with colourful soft corals and shoals of reef fish.
Koh Mook
- Four-island tour — Longtail trip to Koh Chueak, Koh Waen, Koh Ngai and Koh Kradan.
Koh Kradan
- Kradan house reef — Hard and soft corals, clownfish and giant clams a short swim offshore.
- Four-island tour — Longtail loop to Koh Chueak, Koh Waen, Emerald Cave and Koh Ngai.
- Diving around Kradan — Reef dives and trips to nearby Trang pinnacles from local dive operators.
Trang
- Four-island day trip — Emerald Cave, Koh Kradan, Koh Ngai and coral snorkel stops in one day.
Pattaya
- HTMS Khram wreck dive — Former navy ship sunk as an artificial reef near Koh Phai.
Chumphon
- Mu Ko Chumphon National Park — Boat trips to offshore islands with coral and clear water.
- Koh Tao day or overnight trip — Thailand's diving capital lies about 1.5-2 hours offshore by catamaran.
Koh Samet
- Koh Kudee & Koh Talu — Boat trips to nearby islets with clear water, reefs and a pretty sandbar.
- Koh Mun Nai — Small offshore island often combined with snorkelling stops on day tours.
Koh Chang
- Koh Rang Marine Park — The clearest water around Koh Chang, with reef fish and coral gardens.
- Koh Wai & Koh Mak day trip — Island-hop to sleepy neighbours with white sand and turquoise shallows.
- Diving at Hin Luk Bat — Beginner-friendly pinnacle and reef dives south of Koh Chang.
Koh Kood
- Koh Rang snorkelling trip — Boat out to the marine park's reefs for the clearest water nearby.
Frequently asked questions
Where is the best diving in Thailand?
Koh Tao for learning and value, the Similan Islands for world-class reefs and visibility, and Hin Daeng/Hin Muang off Koh Lanta for big pelagics.
Is Thailand good for beginners to learn to dive?
Exceptionally — Koh Tao is one of the cheapest and easiest places in the world to get your PADI Open Water certification.
Can you snorkel without diving?
Absolutely — Bamboo Island, the Similans, Koh Rok and many bays have shallow reefs perfect for snorkelling straight off the boat or beach.
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