Adventures in Diving the Similan Islands


The Similan and Surin Islands are where you will find the best and most diverse diving in Thailand. Famous for their white sandy beaches these National Marine Parks are situated 65km off the coast of Phang Nga Province. Beautiful uninhabited tropical islands surrounded by crystal clear blue water. No wonder the Similan Islands are officially one of the top ten dive sites in the world.
The Surin Islands and the nearby islands and pinnacles Koh Bon, Koh Tachai and Richelieu Rock offer a stunning variety of shapes and colors under water, featuring walls, plateau reefs and pinnacles. International marine biologists stated recently that the Surin National Park posesses the widest coral diversity in all of Southeast Asia.

Click one of the links below to learn more about the dive sites we visit during our day and liveaboard trips.
khao lak scuba dive sitesSimilan Islands
The Similan islands are a string of nine granite islands, providing a breathtaking scenery above and below the water. The Similans are more famous for their rocky dive sites. Enormous granite bolder formations form numerous swim throughs, gullies and canyons.
The islands are fringed by extensive coral reefs and home to a multitude of tropical fish, with frequent sightings of turtles, rays and sharks. Visibility year round averages 30 metres with a sea temperature of 27 – 29oC. All this makes the Similans attractive for both divers and snorkellers alike.

Elephant Head Rock and Christmas Point feature mazes of huge granite boulders lying on top of each other, creating exciting swimthroughs and small caves. Here you can see giant moray eels, lionfish, huge groupers, rays and white tip reef sharks. Soft and stone coral, mixed with sea fans add color to these impressive stone gardens.
The most popular Similan dive sites are: Elephant Head Rock, Christmas Point, East of Eden, The Ridge, Breakfast Bend, Three Trees, Boulder City, Shark Fin Reef and Anita’s Reef.

East of Eden is a very healthy soft and hard coral sloping reef, starting at around 5 metres and reaching up to 30 metres. Here you will find the biggest coral head in the whole of the Similans. Completely covered in soft corals with a huge variety of marine life, it’s possible to see ghost pipefish, nudibranches and anglerfish. You may even be lucky enough to see the friendly resident giant moray.

The Ridge a huge granite rock formation extends down from the healthy hard coral reef to depths of 30 metres plus. The ridge itself is completely covered in gorgonian sea fans, whip corals and barrel sponges. In the shallows we can find a crazy resident Hawksbill turtle who likes to come and say hello! A good spot to see anglerfish, mantis shrimp, rock mover wrasse and reef sharks.

Breakfast Bend and Three Trees are a mix of rocky and reef dive sites. A long stretch of hard coral reef runs along the western part of the island with big boulders in the deep sections. A good place to see leopard sharks, reef sharks, turtles, batfish and barracuda.


oulder City and Shark Fin Reef are rocky dive sites made up of granite canyons with amazing gorgonian sea fans in between. The topography of these dive sites is a sight to behold. Look out for leopard sharks, reef sharks, napolean wrasses, humphead parrotfish, blue spotted stingrays and, due to the location of these dive sites, manta rays have been seen regularly.

khao lak scuba dive sites

Anita’s Reef is the perfect example of the white sand of the Similans mixed with colourful reef and coral heads. A coral head called ‘whole roll of film rock’ can be the hiding place for nudibranches, pipefish and stonefish. In the sandy patches look for garden eels, flounders and sea moths. Although very easy to dive, this site will satisfy beginners and advanced divers equally.
Koh Bon
Koh Bon is an island just a few miles north off the Similans. A round opening on the island’s west point allows you to see straight through this bizarre cliff formation.
Under water, the amazing scenery continues and shows an interesting wall that eventually fades into a long reef stretching down to a maximum depth of 42 metres.

Manta rays are often seen here between November and May. It is a cleaning station for them and you can see them glide slowly past you while the cleaners do their work. The visibility can reach 30 metres and more. The sandy spots at the deeper end are home to blue spotted stingrays, reef sharks and leopard sharks.

A pinnacle on the northern side of Koh Bon offers a good chance for reef shark and large pelagic encounters. The shallowest part of the pinnacle is 16 metres and often this dive can be combined with a ‘big blue’ swim across to the island for a second chance to see the mantas.
Koh Tachai
Koh Tachai is the second island to be found on the way from the Similans to Richelieu Rock. Apart from the pristine white sandy beach, the island offers the best diving in this area.
The main reef plateau, ‘The Dome’ is located approximately 700 metres south off the island and is completely submerged.

The reef offers a plethora of colorful soft, hard and fan corals in combination with rock and boulder formations.

Big schools of barracuda and batfish are regular sightings here and from time to time even the gigantic whale shark finds its way to Koh Tachai.

On the top of the dome look for camoflague experts like the stonefish, find the rare oceanic triggerfish or watch the batfish being cleaned.
Surin Islands
The Surin islands are a National Park hosting some of the last remaining sea gypsies of Southeast Asia. The “Moh Kaen” live in simple bamboo huts use handmade boats to get round the shores of Surin.
Also located on the island is the Surin forestry department that runs frequent turtle release projects and that also enforces the preventation of illegal fishing activities around the islands.

Several dive sites can be found around Surin, each different in reef structure and marine life. Some scientists state that the Surin Islands possess the biggest variety of coral in all of Thailand.

Due to being a perfectly calm and safe mooring destination for liveaboards on their way from / to Similans, Surin is a great stop off point for some dives. The dive sites are a mix of reef and rock, mostly starting at around 3 metres and dropping to maximum depths of 25 metres. There is a huge variety of marine life with chances to see large numbers of humphead parrotfish, many types of sharks, including the guitar shark, and rays.
Richelieu Rock
Worldwide known as the ultimate spot for whale shark diving in the Andaman Sea, Richelieu Rock has much more to offer than “just” big fish encounters.
These pinnacles rise from 40 metres of depth up to the surface but can only be seen during low tide. The pinnacles are completely covered in an amazing variety of beautifully coloured soft corals.

The abundance of marine life will satisfy even the most demanding diver. Camoflague experts such as sea horses, harlequin shrimps, anglerfish, pipefish are all found here. Giant groupers can be found in the deep and nurse sharks, turtles and barracuda are all regular visitors. Lionfish, emperor angelfish, scorpion fish, trevallies and glass fish can be found in large numbers. Between January and April, the chances to meet whale sharks are higher than anywhere else in Southeast Asia.

We can fill this whole website just explaining Richelieu Rock and what you can see there – you’ll have to come to see for yourself!