Diving in Thailand & Burma Diving the Similan Islands in Thailand

Map with the location of the Similan Islands National Marine Park

Map of the Similan Islands National Marine Park

Our liveaboard dive tours to the Similan National Marine Park

  • Similan Dive Safari

    Dive in Thailand at the Similan- and Surin National Marine Park, including Richelieu Rock, Koh Tachai and Koh Bon
    3 days & 3 nights
    10 dives
  • Andaman Dive Safari

    Dive in Thailand at the Similan- and Surin islands at dive sites like Richelieu Rock, Koh Tachai, Koh Bon and Elephant Head
    4 days & 4 nights
    14 dives
  • Dive Adventure 1

    Dive the best of the West Coast of Thailand from south Thailand up north to the border with Myanmar (Burma)
    9 days & 9 nights
    25 dives
  • Dive Adventure 4

    Dive the best of the West Coast of Thailand from south Thailand, incl the southern part of the Mergui Archipelago in Burma
    14 days & 14 nights
    43 dives
  • 1

Diving at Similan National Marine Park

Diving at the Similan Islands

We started to dive at the Similan Islands about 15 years ago and since then we have been diving there regularly during our dive tours. The Mu Koh Similan National Marine Park is suitable for beginning and advanced divers.

Giant boulders and powdered white beaches

The Mu Koh Similan National Marine Park is situated about 90 km south of the Surin National Marine Park in Thailand and covers an area of 128 square km. "Similan" in Malay means 9, recounted that this world-renowned National Marine Park occupies 9 main islands, which are situated in north-south direction.

The whole area is uninhabited by humans with exception of the two National Park offices on island no 4, Koh Miang, and island no 8, Koh Similan.

The lush rainforests are filled with rare wildlife and are offset by huge and bizarrely sculpted granite boulders that make up the mountains and become a divers wonderland beneath the sea. Far from shipping lanes and the mainland, water clarity is excellent with visibility of up to 40m +.

Dive with manta rays at the Similan Islands

The dramatic underwater terrain is highlighted by awesome geological formations, thriving reefs with an abundance of soft corals and a diverse collection of marine life, particular fish species and frequent visits of pelagics like manta rays and sometimes whale sharks.

Although the dive site Koh Bon is the most frequently visited site by manta rays, you can also have a good chance to dive with manta rays at Koh Tachai and Richelieu Rock. During rare occasions we also dive with them at other dive sites like Elephant Head or Gorgonian Valley.

Dive sites at the eastern shores

Dive sites along the eastern shores of the Similan's feature gently sloping reefs and drop-offs with impressive fields of sea anemones, teeming fish population and flourishing hard corals and soft corals.

With gentle currents and mostly moderate depths, these sites are suitable for any level of diving skill and are also perfect for snorkeling.

Dive sites at the western shores

The western dive sites are quite the opposite. Giant boulders meet up with the seabed at 30 meters or more. The gaps between these boulders, channel the open ocean through, creating moderate to strong currents.

The water is very clear, yet nutrient rich; there is no sedimentation or sand build up, and the water action has created massive networks of arches and swim through's that provide extremely exciting diving. The high availability of nutrients in the water also provide the raw materials for the food chain, with masses of gorgonian's, crinoids, sea fans and soft corals filtering the plank tonic bounty.

Manta rays at the dive site Koh Bon. Divers can have sightings with manta rays here frequently


Nudibranch at the Similan Islands. Within the Similan National Marine Park you can find colorful nudibranchs in all sizes and colors


Granite rocks of the Similan Islands. These rocks create the special landscape and atmosphere of the Similan Islands, as well above- as underwater..


More dive destinations

Diving at the Mergui Archipelago in Myanmar (Burma)

The Mergui Archipelago

Diving at the Surin National Marine Park

Surin National Marine Park

Diving around Phuket in Thailand

Diving around Phuket

Diving in Southern Thailand

Diving in Southern Thailand

Dive sites of the Mu Koh Similan Islands National Marine Park

At Shark Fin Reef the underwater terrain is marked by huge boulders, which are a common sight at the Mu Koh Similan National Marine Park in Thailand

Shark Fin Reef

Shark Fin Reef is situated in the southern part of the Similan Islands National Marine Park.

The dive site is a kilometer long huge rock which breaks the surface as it's base.

Here we find several dive spots like "The Hong" in the north-western part.

The north-east / south-western side, with a long rock and a pinnacle, offer swim throughs.

Along with currents, we can follow varying dive routes here during different dives.

Usually visibility is about 20-30m+.  It's one of our favourite dive spots at the Similan islands.

Koh Tachai offers multiple dive sites. The dive site Koh Tachai Plateau is the common dive site of the dive sites at the dive destination Koh Tachai

Koh Tachai Plateau

Koh Tachai has one of the most spectacular coral gardens in the Andaman Sea.

Interspersed with huge granite boulders -which form a series of plateaus that descends down to 40m-, the reefs stretches out in all directions and form a dive site with thrilling sceneries.

It's heaven for fish here, they hunt and dart around in schools and solely free, coming very close to divers and making the diving here about as exiting as it gets here in Thailand.

Giant manta rays are often spotted there and during the lsat season we saw lots of whale sharks here.

Koh Tachai Pinnacle is the deeper dive site of the Koh Tachai dive area. Whale sharks sometimes visit this area for plankton which is abundant due to common slight and stronger currents

Tachai Pinnacle

Situated between the plateau and the island of Koh Tachai, we find the pinnacle as a single dive site.

Starting 10m below the surface, the area around drops to 25-30m. You'll find a beautiful underwater landscape with nice sea fan gardens and lots of soft corals.

A healthy population of reef fishes are home to Koh Tachai Pinnacle. In the outer sands, you may find leopard sharks resting during daytime.

It is also possible to start the dive at Koh Tachai Pinnacle and end the dive at Koh Tachai Plateau.

Manta rays sometimes visit the dive sites of Koh Tachai too...

Gorgonian Valley

Gorgonian Valley

This is one of the deepest dive sites of the Mu Koh Similan Islands National Marine Park and is situated in the southern area of the park.

This is fully submerged dive site and offers a big area which is divided in three parts. You'll find throughout a big boulder scenery with lots of sea fans.

If the current comes the right way, we can drift along the whole area.

Gorgonian Valley is a good spot to see barracudas, tunas, rainbow runners, leopard sharks and occasionally manta rays or whale sharks.

The visibility is usually very good on this open ocean dive site.

Koh Bon Pinnacle is the deeper situated dive site of Koh Bon Island, which is located at the west coast of Thailand. At Koh Bon you can find often larger schools of predator fishes, like tunas, barracudas and mackerels.

Koh Bon Pinnacle

Koh Bon is an Island about one to one and half hours north east of the Similan Islands. The pinnacle is about 100 meters of the north-west corner of the island.

The top of the pinnacle is at about 18 metres and slopes down steeply to 40 metres on the north and 35 metres on the south.

The pinnacle is covered primarily with yellow soft corals, though there is a certain amount of variation happening. There is plenty of small reef life to watch here but you’re really here for the big stuff. Huge groups of giant trevallies circle the rock and you’re often joined by the resident pair of napoleon wrasses. Manta rays and eagle rays are regularly spotted here.

Koh Bon Wall

Koh Bon Wall

We dive at Koh Bon Wall at the beginning or end of a dive when we dive at the main dive site Koh Bon. For beginning divers, we'll stay mainly at the wall as it allows us to descend/ascend easily, while focusing on the walls.

The wall is covered with smaller yellow soft corals and small marine life lives inbetween. Always look over your shoulder here: manta rays and whale sharks may pass behind you when you look at the wall only...

East of Eden

East of Eden

This dive site is the best of all the east coast dive sites of the Similan Islands. East of Eden is known for its delicate hard coral reef sloping from about 8m down to 30m.

The nicest here is to dive with a slight drift, which offers a effortless slowly dive along the whole reef.

While you'll enjoy the sightings of the reef, you'll also find lots of juveniles during particular months here.

The highlight of this dive site, is a huge bommie at the end of the dive, which is covered in huge sea fans and which is surrounded by glass fishes. The sightings here give astonishing views.