Richelieu Rock (Hin Plo Naam) is a horseshoe-shaped rock close by the border to the Union of Myanmar. It was first discovered by Jacques-Yves Cousteau and has been since one of the most astonishing dive site around the world. The dive site is part of the It is part of the Koh Surin Marine National Park and lies about 18 km east of the islands.

The dive site is covered by purple soft corals and hosts a huge diversity of marine life. From small fish to schooling mackerel or barracudas as well as larger pelagic fish you can spot almost everything here. Richelieu Rock is one of the best dive sites to see Whalesharks in Thailand but also if you like tiny creatures such as frogfish, harlequin shrimps or ghostpipe fish you should not miss this spot.

The dive site starts right beneath the surface and the deepest part ends around 50 meters. Strong currents can be encountered here, that´s why you should have done a check dive before diving this amazing place.