Diving in Thailand

The Similan Islands

Thailand's most beautiful and diverse group of islands, liveaboards to the Similan Islands are some of the most popular diving cruises in the world, and certainly the best diving in Thailand. They comprise nine granite islands covered in tropical jungle, washed by a clear blue tropical ocean and blessed with fine beaches. They lie in a 25 km long north-south chain, 65 km offshore from Phang Nga Province in the Andaman Sea. The Similan Islands National Marine Park, which also includes Koh Bon Island to the north west, was opened in 1982 and it is now fully protected.

The eastern side of the islands features hard coral gardens which slope dramatically from the surface down to thirty metres. At several of the sites large coral bommies rise from the bottom and are covered with soft corals, sea fans, and an enormous amount of unusual fish. Here Similan diving is easy and navigation simple, allowing you to explore at your leisure.

The western side, north and south points of the Similan Islands can offer faster paced, more exhilarating diving as currents swirl around the huge granite boulders. These smooth, rounded boulders make dramatic formations, overhangs and swim-throughs. The drama of just looking up through the clear water at these majestic rocks is satisfaction enough for some scuba divers, as there are few places on earth like this. Growing on these boulders are some of the most colourful soft corals imaginable. In the larger passages or channels between the boulders, the fans can grow to three metres, and are often so tightly packed that it makes it impossible to swim through.

If you enjoy watching and photographing small fish, then Similan Islands diving is hard to beat for the sheer numbers and varieties of tropical fish. Leopard sharks make appearances on a regular basis and we also see white tip and black tip reef sharks.

At a few of the sites, gorgonian fans and hard corals were broken and over-turned by the tsunami of December 2005, but there are many sites that survived without any significant damage. The Similans remain the premiere destination for diving in Thailand.

• Map of Similan Islands

Diving in Thailand - Dive Season

The best conditions for scuba diving in the Similan Islands exist from November to April. Surface conditions are ideal and visibility is optimal.

The liveaboard season runs from early October to mid May, but there are a limited number of cruises to the islands all year round. Please note though that outside of these months, the seas are unpredictable and cruises can be cancelled at short notice due to high seas.

Similan Islands Reef Basics

Great for: Small animals, underwater photography, snorkelling, visibility, dive value-for-money and advanced divers
Not so great for: Non-diving activities
Depth: 5 - >40m
Visibility: 20 - 40m
Currents: Moderate
Surface Conditions: Calm
Water Temperature: 26 - 29°C
Experience Level: Intermediate - advanced
Number of dive sites: >25
Distance: ~90 km northwest of Phuket (5 hours), 65 km west of Khao Lak (3 hours)
Access: Thailand liveaboards to Similan and Burma
Recommended length of stay: 4 - 6 days

Dive The World Recommendations: Christmas Point, Elephant Head Rock and Batfish Bend.

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• Dive Burma liveaboard enquiries

Back to Thailand diving sites index

For more on the individual dive sites of this destination, visit our Dive The World Thailand website:
• Similan Islands diving sites