Richelieu Rock, also called Hin Plo Naam in Thai, is a dive site located 18 km from Ko Surin Tai Island in Thailand. It is not only considered the most beautiful diving spot in Thailand but is also one of the top 10 places in the world to enjoy marine life. If you plan to make a diving trip in Thailand, you should know that in terms of depth the Richelieu Rock diving spot can reach up to 40 meters. As for the visibility, it is between 10 to 30 meters. The current goes from low to high. The best time to visit Richelieu rock is between October and early May, but from February to April you will encounter more pelagics such as whale sharks or mantas, reef sharks and more.

The history of rock Richelieu Rock
The spot was named Richelieu by an admiral. This admiral, obviously called Richelieu, was a commander of the Royal Thai Navy. He was responsible for mapping the scene. It was in 1960 that this site was explored for the first time by Commander Jacques-Yves Cousteau. Moved by the beauty of Richelieu, Cousteau wanted the world to know it. It is true that this spot is a real reserve of marine biotopes. The rising currents are full of plankton. No need to ask what might attract whale sharks to this site. Despite potential currents, Richelieu can be frequented by divers of all levels. With a depth of 40 meters, diving is interesting only between 0 and 20 meters. In general, the visibility is good, but note also that the region regularly undergoes storms which makes currents sometimes strong. In order to make sure that you won’t have to cancel your diving trip, make sure to choose the right season.
Where is Richelieu Rock on a map
Some people describe the dive site Richelieu Rock as a huge rock in the shape of a crescent while others argue that it looks like a gigantic horseshoe. At low tide, you can see the top of the submerged rock that lies at a depth of 50 meters. Thais call him “Hin Ploo Naam”, which means “rock coming out of the water”. The dive spot is populated by sea anemones and multicolored corals. The south side slopes gently, unlike the north face which, in addition to imposing a vertical descent, also has walls and several rocky corridors. Richelieu deserves at least five different dives in order to be fully discovered. The numerous rocks which compose it abound with extraordinary marine life.

Marine life in Similan Islands
Lovers of big and small fish, you will all be satisfied. In Richelieu, you just have to look up to meet the biggest fish in the world: the whale shark. The dive site Richelieu rock is definitely one of the best place to dive with whale sharks. There is also one of the largest species of rays: the manta. Above the reef, you will see many barracudas. A wonderful show to see! To see black tip sharks, giant moray eels or giant groupers, dive to the bottom. Photography enthusiasts are not left out. Multicolored soft corals are a real hideaway for nudibranchs, porcelain crabs, harlequin shrimps, seahorses, frogfish, pipefish and many more. On the side of the anemones, you will also find the famous clownfish, cuttlefish, angelfish and many other coral fishes.
Diving cruise in Richelieu Rock
It is possible to discover Richelieu rock thanks to some dive centers based in Khao Lak but it will take hours of boats and it is far from being convenient. The best way to discover Richelieu rock is to book a liveaboard in the similans island in Thailand.There is nothing better than this type of expedition to discover Richelieu rock as well as the other diving spots of the Similan Islands like Koh Bon and Koh Tachai, also known for the beauty of their spots. In general, this lasts 4 days and each dive is supervised by qualified instructors who know the sites by heart.
If you have any tips or advice on diving in Richelieu Rock, feel free to share them as a comment.