Also found within Mu Koh Similan Marine Park is a little island named 'Koh Bon'. Koh Bon is about 20km north of the Similan group and is noteworthy as it has two dive sites that frequently double as manta ray playground.

One of these sites is a wall dive which starts in the bay and concludes at a beautiful rock ridge with overhangs.

The second dive site is a submerged pinnacle, close to the island, which seems to be the spot where many leopard sharks go to relax.

Koh Bon is a famous dive site because divers have here quite reguarly amazing encounters with manta rays. Manta rays are very common here during the dive season, and this dive site is definitely one of their favourite spots to hang out.

Two hours south from the Surin Islands, we encounter Koh Tachai, which has one of the most spectacular coral gardens interspersed with huge granite boulders, which form a series of plateaus that descends down to 40m.

There are many sea fans, colorful soft corals, moray eels, leopard sharks and schools of batfish to name just some.

Giant manta rays are often spotted there.

Richelieu Rock lies just 12km east of the Surin island group. This amazing pinnacle is the only seamount in the area, and rises to the surface from a great depth.

This environment provides a home to large schools of Big Open Ocean (pelagic) fishes, many predators and is frequently visited by whale sharks and giant manta rays.

The rock is covered with forests of brilliantly colored soft corals and has abundance of smaller fish and other reef life.

Mu Koh Surin lies approximately 64 km due southwest of Koh Chang in the Andaman Sea, very close to the oceanic border between Thailand and Burma.

This marine park consists of a group of 5 islands, the largest being Koh Surin Nua (North Surin Island) which covers an area of 19 square km. To the immediate southwest lies Koh Surin Tai (South Surin Island), which is slightly smaller with an area of 12 square km. Between these two main islands is a 200 m wide channel which can be crossed by foot at low tide.

The fringing reefs here are shallow and slope gently to the sea floor. For this, Surin is renowned for its fine snorkeling and free diving. There are excellent scuba diving sites that range in depth from 10 to 25m, such as 'Turtle Ledge', (named for the Hawksbill turtles that are frequently sighted there) and 'Baggard Bay', with its gorgeous reefs and calm waters.

For the more experienced and adventurous, there are drift dives through the magical gardens of 'Swift Passage', deep dives at 'Hin Rap' and 'South Torinla' and wall diving on the sheer, submerged pinnacles of 'Little Richi' and 'Marshall Reef'.