Richelieu Rock
Thailand · Andaman Sea
Richelieu Rock is a horseshoe shaped pinnacle in the Andaman Sea that rises just to the surface — a single seamount draped in purple soft coral with whale sharks, barracuda schools, frogfish, and an extraordinary macro layer. Jacques Cousteau called it one of the world's top ten dives.
How this reef is doing
ⓘ How we measure thisReef state
Pinnacle dive — fish life and macro, not extensive coral. Whale shark season Feb–Apr is the highlight.
Coral cover
Fish life
Heat
Warmer than usual right now, but not hot enough to bleach.
Fishing
Quiet water, and the protection is actively patrolled.
Sources · MERMAID and partner coral surveys · NOAA Coral Reef Watch · Global Fishing Watch and reef gravity
What you will see
10 species across the dive sites here
Whale shark
Seen 1 month ago
at Richelieu Rock
Endangered
Oceanic manta ray
Seen 2 months ago
at Hin Daeng / Hin Muang
Endangered
Tigertail seahorse
Seen 4 months ago
at Richelieu Rock
Endangered
Schooling barracuda
Seen 4 months ago
at Richelieu Rock
Least concern
Giant trevally
Seen 6 months ago
at Hin Daeng / Hin Muang
Least concern
Cuttlefish
Seen year round
at Richelieu Rock
Least concern
Grey reef shark
Seen year round
at Hin Daeng / Hin Muang
Endangered
Leopard (zebra) shark
Seen year round
at Hin Daeng / Hin Muang
Endangered
Schooling chevron barracuda
Seen year round
at Hin Daeng / Hin Muang
Tomato anemonefish
Seen year round
at Richelieu Rock
Least concern
Dive sites
What divers say
Richelieu in March with a whale shark sliding around the rock — I've chased that dive every year since.
Good to know
Park closure
Closed mid-May to mid-October. Confirm yearly.
Liveaboard preferred
Day-trips are 4h each way; liveaboards do it before/after the crowds.