Koh Bon, Koh Ta Chai, Richelieu Rock and the Surin Islands National Park lie to the North of the Similan Islands, close to the Burmese border. Many liveaboard tours from Phuket will visit these dive sites. Click on the links above for liveaboard boat information. The islands offer a wealth of smaller underwater life and a great chance to see passing manta rays and whale sharks - encounters with these magnificent giants are not uncommon around Richelieu Rock.
Surin Islands Divesites
Richelieu Rock
Some 50 nautical miles North of the Similan Islands lies one of the best known dive sites in Thailand. Just breaking the surface at low tide, Richelieu Rock is probably your best chance to have the whale shark experience. Some years ago, this site was regarded as a "whale shark magnet", and while this is now somewhat of an exaggeration, they still visit regularly, especially from February to May.
Other large pelagics such as eagle and manta rays are occasional visitors to Richelieu Rock. The dive site is huge and most liveaboard tours will schedule more than one dive here. The sheer variety of life is amazing. Huge schools of trevallies and barracudas cruise the currents, and many tiny critters such as frogfish, ghost pipefish, harlequin shrimps and seahorses are hiding in crevices.
Koh Tachai
The island of Koh Tachai lies about 20 nautical miles South of Richelieu Rock and can be another great spot for Manta Rays. The dive site is a submerged sea mount with depths from 14-35m and currents can be quite strong. The top of the reef is a beautiful mixture of hard corals, while deeper regions consist of scattered boulders and sea fans. Leopard sharks are commonly found resting on the bottom, while schools of barracuda and batfish cruise around the reef.
Koh Bon
Koh Bon is only a short cruise North of the Similan Islands and is without doubt the best site for Manta Rays. The dive site follows a ridge, covered in pastel shaded soft corals, which drops to depths of 35-40m. Mantas are often spotted over the ridge or in the deep water to the South. Leopard sharks are also common in the deeper water. Another deeper site "Koh Bon Pinnacle" is also dived by some boats, but is not really recommended for beginners.
