Thailand Diving Sites

First discovered as a scuba diving site by Jacques Cousteau, Richelieu Rock rises from a maximum depth of 50m to just reach the surface. The rock boasts great biodiversity too and is worth several dives, with or without whale sharks. It consists of a main horseshoe shaped splintered rock pinnacle, with several other smaller rocks around its edges. The limestone rocks are covered with anemones, sea fans, barrel sponges and soft corals of all kinds. From tomato anemone fish, yellow boxfish, white-eyed moray eels and mantis shrimps to nurse sharks, manta rays, 1 metre Malabar groupers and chevron barracuda, there's always plenty of life to grab your attention on a dive at Richelieu Rock.

The problem for underwater photographers diving here is which lens to dive with. On the one hand there's the resident frogfish and seahorses that make such willing macro photo subjects. Mating cuttlefish and octopus are also common sights. Then on the other hand, there's the chance of something really big swimming by and leaving you wishing that you'd selected your wide angle lens!

Richelieu Rock can be a deep dive but there is also plenty to see at shallow depths all the way to the surface. When the currents are strong there are always places to find shelter.

Richelieu lies between the Similan Islands and the Surin Islands. This stretch of the Andaman Sea also includes the two islands of Koh Bon and Koh Tachai that are good diving locations in their own right. The best way to dive here is on a liveaboard cruise. All of the Similan tour operators include Richelieu Rock as part of their itinerary and a few of the longer cruises also push on to Surin. You can expect a minimum of a 4 night cruise if you want to reach this renowned diving site.

It is possible to dive here only from late October to early May, due to rough sea conditions prohibiting diving outside of this period. During the diving season the conditions are generally good and liveaboards make regular visits. The driest months are February and March and they also see regular flat seas that make this the ideal time to visit Richelieu Rock.

The water temperature is usually around 30°C at the surface and 27/28°C at depth, although in November and December transitional thermoclines can cause temperature drops to 25°C. It should be noted that underwater visibility at Richelieu is often reduced from March to April due to a higher density of plankton in the water. However, this is not an unwelcome event since this is what attracts the whale sharks.