Best Diving in Thailand 2026
Thailand is one of the world's great diving destinations, from the beginner-friendly waters of Koh Tao to the pristine Similan Islands and legendary Richelieu Rock. Here's where to dive and when.
Quick Answer
Where is the best diving in Thailand?
For beginner certification: Koh Tao — the world's most popular scuba training destination. For experienced divers seeking the best underwater scenery: the Similan Islands and Richelieu Rock via liveaboard from Khao Lak. For accessible day-trip diving with reef sharks: Koh Phi Phi. For pristine marine park diving: Koh Lipe.
Similan Islands seasonal closure
Koh Tao
Best season
Year-round (best March–October)
Visibility
10–25m
PADI cost
฿9,500–฿12,000 (Open Water)
Koh Tao is the world capital of budget scuba diving. More PADI Open Water certifications are issued here than anywhere else on earth. The dive sites encircling the island range from the gentle Aow Leuk bay (perfect for beginners) to the advanced Japanese Gardens and Southwest Pinnacle with its whale shark and manta ray sightings. Sail Rock, a 45-minute boat ride north, is one of the Gulf's premier advanced dives — a submerged pinnacle with a chimney passage and frequent whale shark encounters. Competition among the island's 100+ dive schools keeps prices low and maintains high safety standards.
Full Koh Tao guide →Similan Islands
Best season
November–April (park closed May–October)
Visibility
20–40m
PADI cost
฿20,000–฿45,000 (liveaboard, 3–4 nights)
The Similan Islands National Park, accessed via liveaboard from Khao Lak, is Thailand's premier diving destination — and one of the best in all of Asia. Nine granite islands sit in the middle of the Andaman Sea surrounded by crystal-clear water with visibility frequently exceeding 30 metres. Hard coral gardens, dramatic underwater boulders, and abundant pelagic life including manta rays, leopard sharks, and occasional whale sharks are the draw. Richelieu Rock (technically in a separate park to the north) is often combined on liveaboard itineraries and is frequently cited as Thailand's single best dive site.
Full Similan Islands guide →Richelieu Rock
Best season
November–April
Visibility
15–30m
PADI cost
Accessible by liveaboard only (฿25,000–฿45,000)
Richelieu Rock is a submerged horseshoe-shaped pinnacle in the Surin Islands Marine Park, reachable only by liveaboard. Jacques Cousteau reportedly called it the most beautiful dive site in the world. The site is famous for its dense soft coral coverage — pink, purple, orange — and an astonishing density of marine life. Whale sharks visit regularly from March to May. Seahorses, ghost pipefish, and harlequin shrimp hide in the coral. The current can be strong, making this a dive better suited to intermediate and advanced divers.
Full Richelieu Rock guide →Koh Phi Phi
Best season
October–May
Visibility
10–25m
PADI cost
฿1,500–฿2,500 (day trips) / ฿10,000–฿13,000 (Open Water)
Koh Phi Phi's dive sites offer good variety for day-trip divers staying on the island. Bida Nok and Bida Nai are the signature sites — two limestone pinnacles rising from around 18m to just below the surface, covered in hard coral and frequented by blacktip reef sharks and leopard sharks. Hin Phae and Maya Bay's underwater area attract dive-trippers from the main beach. Diving at Phi Phi is more accessible and convenient than liveaboard options and suits travellers who want good diving without committing to a dedicated dive trip.
Full Koh Phi Phi guide →Koh Lipe
Best season
November–May
Visibility
15–30m
PADI cost
฿10,000–฿12,000 (Open Water)
Koh Lipe in the far south of the Andaman Sea sits within the Tarutao National Marine Park — one of Thailand's most strictly protected marine environments. The result is notably pristine coral and marine life compared with more heavily dived areas. The dive sites around Koh Lipe, Koh Adang, and Koh Rawi offer clear water, healthy hard and soft coral, and regular sightings of reef sharks, turtles, and rays. Koh Lipe is less established as a dive destination than Koh Tao or Phi Phi, which means smaller groups and a less commercialised experience.
Full Koh Lipe guide →