The Similan Islands & Surin National Marine Parks

The Similan Islands Dive Sites are located 70 kilometers off the west coast of Phang Nga Province.  The small archipelago of the Similan Marine National Park, consisting of nine islands, run south to north and have become world renowned for being the best dive destination in Thailand.  Their name comes from the word ‘sembilan’ – meaning ‘nine’ in the Yawi dialect spoken in southern Thailand and the northern Malay states.  The Similan Islands gained the status of Thailand’s 43rd national park in 1982 and also includes the Island of Koh Bon. In 1998, the park was extended to include the island of Koh Tachai, bringing the total park area to 140km2 – only 15km2 of this is actually land.


The Similan Islands
Islands north of the Similan Islands
Boonsung Wreck

Similan Islands Dive Sites

Each Similan island has its own local name but for most (especially within the local scuba diving community) they are named by number, the first being Island 1 in the south and ending with Island 9 in the north. Islands No. 1 through No. 3 are protected areas and closed to the public – sea turtle, coral and marine life rehabilitation are the key concerns here. For the majority of visitors the Similan Islands start at Island No. 4 (Koh Miang), and it is here you get you first impression of the islands topography.

The east and west sides of the Similan islands Dive Sites differ greatly, the low season monsoon that runs from May through to October attacks the islands from the south west in the form of high winds, rains, waves. As a result of this exposure, the west side to all the Similan Islands has been weathered to expose the granite bedrock and boulders.

The west side of the islands could not be more different. It is here you will find their famous white sand beaches, stacked granite boulders, and viewpoints so popular with the beach lovers. Below the waterline offers an equally contrasting seascape were you’ll discover the huge variety of reef species, colourful soft corals and hard coral that live on these sandy bottomed reefs and gently descend to 30-40 meters.

Further North

A two and a half hour cruise north of the Similan Islands Dive Sites will bring you into the waters of Mu Ko Surin National Park. Around 18 kms east of the Surin Islands, we will take you to the world famous underwater formation, Richelieu Rock. The rock consists of one main, horse shoe shaped pinnacle, with several other smaller rocks around its edges. The site is totally submerged, except at low tide when the tip breaks the surface. World famous and regarded as the best dive site in Thailand, Richelieu Rock remains the highlight dive during our five day cruise around these stunning National Parks.

The Similan and Surin National Marine Parks are only open to visitors between the months of mid-October to mid-May each year. In the low season the park is closed in an attempt to preserve the sites from unnecessary damage and also because the low season monsoon does not allow for safe or comfortable cruising during the closed season.