Richelieu Rock rates as one of the best places in the world to dive with whale sharks and is easily the best site in Thailand diving for this amazing activity. Encounters with the whale sharks, the largest fish in the ocean, are rare almost everywhere in the world.
It's not the only Thailand dive destination where whale sharks are seen but Richelieu Rock certainly attracts more than its fair share.
With nothing else for miles around, the whale sharks are attracted to the rock to feed on the rich planktonic blooms that occur here.
A liveaboard charter is your best bet for diving here, as once they arrive, they tend to hang around for days, with an entourage of followers in tow, most notably cobias.
Swimming with such a large animal, known to grow to fourteen metres in length, is a never to be forgotten experience for any diver.
Sightings occur about 10% of the time. Some dive seasons see more visitors than others and generally February to April is the best time for a visit if your aim is to enjoy the exhilaration of swimming with these massive creatures onboard Liveaboards in Thailand.
Richelieu Rock boasts great biodiversity too and is worth several dives, with or without whale sharks.
It consists of one main, horse shoe 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, one metre Malabar groupers and chevron barracuda, there's always plenty of life to grab your attention on this dive.
The problem for underwater photographers diving Richelieu Rock is which lens should you dive with.