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Scuba Diving in the Similan Islands

The Similan Islands is an archipelago in the Andaman Sea. "Similan" (from the Malay sembilan) means “nine”. Each of the nine Similan Islands has a name and a number. What makes these islands so attractive are the large boulders found on the shores of several of the islands. The picturesque white-sand beaches are quite a splendid sight as well. But it’s also what lies under the pristine waters that has turned the archipelago into a favorite destination for tour boats.

Similan Islands Diving Info

The Similan Islands are often rated as one of the best dive destinations in the world. Why? For instance, the diving is rich in large pelagics in season and the colorful coral reefs are pulsating with life all shapes and sizes. Divers can choose from about 20 dive sites.

The Similan Islands are only accessible by liveaboard. The good thing is, the liveaboard costs here are more affordable than other renowned dive destinations in the world. The liveaboard season runs from November to April.

whale shark similan islands
Whale shark spotted at Similan Islands. Photo by Abe Khao Lak

When to Visit

The Similan National Park is open from November 1st through May 15th, but February and March offer the smoothest water and least amount of rain. The peak travel period runs December through January, and you’ll have to book your liveaboard well in advance if you want to visit the Similan Islands during these months.

Water Temperature

The water temperature in the Similan Islands is absolutely perfect, ranging between 27°C and 30°C (80-86° F).


The Similan Islands exposed to current, specifically dives sites like Elephant Head Rock, Richelieu Rock, and Koh Tachai Pinnacle that are hit by moderate to strong currents. Currents are the strongest in February.


The visibility in the Similan Islands is good to great all year, ranging from 20 meters to over 30 meters (66 to over 98 feet).

Types of Diving

  • Reef diving
  • Drift diving
  • Wall diving
  • Night diving

Similan Islands Diving Highlights

Marine Life

crab similan islands
Anemone crab. Photo by prilfish

The complex ecosystem found underwater around the Similan Islands is often referred to as the rainforest of the sea. The list of marine life that divers have the chance of seeing is exhaustive and there are several books dedicate to it. You can find these books on the liveaboards heading to the islands.

Just some of the countless marine animals you can spot in the Similan Islands include manta rays, whale sharks, black-tip sharks, white-tip sharks, leopard sharks, Hawksbill turtles, giant barracudas, shovelnose rays, eagle rays, seahorses, various species of sweetlips of triggerfish, giant jellyfish, Napoleon wrasses, octopus, cuttlefish, giant groupers, snappers, lionfish, and the list could go on and on.


Divers taking a plunge at the Similan Islands can feast their eyes on a plethora of both hard and soft coral, as well as sea anemones. The Andaman Sea provides the ideal conditions for coral reefs to grow and flourish. The reefs in the Similan Islands grow down to a depth of about 30 meters (98 feet).

The hard corals here are mostly deep-water staghorn types but there are also some varieties of brain-shaped coral. They co-exist with other species of underwater flora such as Gorgonian sea fans. Richelieu Rock, part of the Mu Koh Surin marine park, is the most colorful dive site in the area. The horseshoe-shaped reef is known for its beautiful red and purple soft corals.

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Dive sites in the area:

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Richelieu Rock

Similan Islands, Phang Nga

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Elephant Head

Similan Islands, Phang Nga

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Turtle Rock

Similan Islands, Phang Nga

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Donald Duck Bay

Similan Islands, Phang Nga

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Western Rocky

Similan Islands, Phang Nga

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Princess Bay

Miang Island, Similan Islands

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West Of Eden

Payu Island, Similan Islands

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North Point

Bangu Island, Similan Islands

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Three Trees

Bangu Island, Similan Islands

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Atlantis Wreck

Similan Islands, Phang Nga

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