Similan Islands - Diving the Similans
Thailand's Favourite National Marine Park

Comprising nine granite islands covered in tropical jungle, washed by a clear blue tropical ocean and blessed with fine beaches, the Similan Islands provide the most beautiful and diverse dive destination in Thailand. Liveaboards to these islands are some of the most popular diving cruises in the world. They lie in a 25 km long north-south chain, 65 km offshore from Phang Nga Province in the Andaman Sea, about 100km from Phuket. The Similans achieved National Marine Park status in 1982.
The eastern fringes of the islands feature pretty hard coral gardens in the shallows and sloping reef banks down to thirty metres. At some dive sites such as East of Eden, large bommies (coral heads) rise from the sea bed and are blanketed with soft corals, fan corals, and swarms of smaller tropical fish. East coast Similan Islands diving is relatively easy-going, allowing you plenty of time to explore the sites at your own leisurely pace.
The western side of the Similans along with the north and south points can offer more exciting diving as currents swirl around huge sunken granite boulders, which form a series of arches, tunnels and swim-throughs at sites such as Christmas Point and Elephant Head Rock. Growing on, and between, these enormous rocks you find a tapestry of colourful soft corals. In the channels between the boulders, sea fans can grow to some three metres across, and in such numbers that you cannot possibly swim through. The contrast between the east and west coasts and the variety of underwater topography is one of the reasons the Similan Islands are so popular - every dive offers you something different.
For underwater photographers and lovers of marine life, then diving in the Similan Islands is difficult to surpass for the variety and abundance of tropical fish. Leopard sharks make appearances on a regular basis and you'll also see whitetip sharks. It's not a 'big fish' paradise, but it's consistently great for sheer diversity of marine life. You may find anything from tiny ghost pipefish to turtles and giant bumphead parrotfish.
Although the tsunami of 2004 did affect a few of the reefs here, most are in excellent condition and many divers in the last season have commented to us that they could not see any reef damage.
• Koh Similan tourist information
• Map of the Similan Islands
How to Dive the Similans

Similan liveaboards remain the best choice to dive at these islands. There are well over 25 dive sites here, spread over quite a large area and far from the mainland. So, to truly experience all that they have to offer at a relaxed pace, we strongly recommend you choose a liveaboard.
If you are short of time or prefer land based diving, then there are many day trips packages, with and without accommodation, to choose from. Check out the options in the blue box on the right hand side of this page.
As a final alternative, there are a number of overnight trips that offer Similan Islands diving opportunities. These operate with daily speedboats from the mainland that run you out to a main diving boat that you can sleep on. You can disembark whenever you like. These trips are cheap and very popular with budget travelers, but have constant disruptions for re-fueling and passenger transfers, and are therefore not always the most pleasant way to experience the Similans.
Similan Islands Diving Season
Scuba day trips and overnight trips run from October through to May, with the very best conditions existing from November to April. Outside of these months, surface swells can adversely affect conditions. From May to August, the weather is often better in the Gulf of Thailand, so you might consider day trip diving in Koh Samui, although local diving around Phuket and Phi Phi continues year round too.
The Similan Island liveaboard season runs from early October to mid May, but there are a limited number of cruises all year round.
Similans Reef Basics
Great for: Small animals, underwater photography, snorkeling, 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, or 1½ hours by speed boat)
Access: Similan islands diving liveaboards and day trips from Phuket
Recommended length of stay: 4 - 6 days
Dive Sites
More detailed information on the Similan Islands dive sites:
Dive The World Recommendations: Christmas Point, Elephant Head Rock and Batfish Bend.
Other nearby sites that can be dived on liveaboards and day trips, together with the Similans:
Other nearby sites that can only be visited on extended Similans liveaboards:
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