Richelieu Rock is one of Thailand’s most famous dive sites and a highlight of diving from Khao Lak.
Located near the Surin Islands, this horseshoe-shaped pinnacle drops to around 35 metres and is covered with colourful soft corals, sea fans, anemones and small overhangs.
Famous for huge schools of fish and fantastic macro life, Richelieu Rock is also one of the places in Thailand where whale sharks are occasionally seen.
There is so much marine life here that two dives can feel completely different.
Expect schools of snapper, barracuda and trevally, together with moray eels, cuttlefish and lionfish. Look closer and you may find seahorses, ghost pipefish, nudibranchs and harlequin shrimp.
And remember — keep your eyes and ears open for the unexpected.
If you hear your guide banging on their tank, look up!
The first dive normally explores the deeper outside of the horseshoe, depending on the current and conditions.
Look amongst the sea fans and corals for seahorses and other small marine life as you gradually make your way shallower.
Don’t spend the whole dive looking at the rock — something much bigger could be swimming behind you.
The second dive gives you another chance to explore Richelieu Rock, often concentrating on the shallower areas and inside of the horseshoe.
Take your time looking into the cracks and crevices. Cuttlefish, moray eels, nudibranchs and tiny critters can be hiding almost anywhere.
Our dive site map shows the distinctive horseshoe shape, depths and main areas of Richelieu Rock.
The actual dive route will depend on the current and conditions on the day.
Richelieu Rock can be visited on selected diving day trips from Khao Lak during the Similan and Surin diving season.
It is also included on many Similan and Surin liveaboard itineraries.
Contact Pirate Divers Khao Lak and tell us your certification, diving experience and preferred dates. We’ll help you find the best option for diving Richelieu Rock.