Scuba Season
Underwater reef at Richelieu Rock
Stable

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 this

Reef state

Stable

Pinnacle dive — fish life and macro, not extensive coral. Whale shark season Feb–Apr is the highlight.

Coral cover

36%
LowHealthy
Moderate

Fish life

Not surveyed

Heat

SafeBleaching

Warmer than usual right now, but not hot enough to bleach.

Warming

Fishing

QuietBusy

Quiet water, and the protection is actively patrolled.

Patrolled

Sources · GCRMN reef surveys · NOAA Coral Reef Watch · Global Fishing Watch and reef gravity

Coral cover over time

Live coral cover, by survey year

Across surveys in 2014 and 2024, live coral cover here has fallen from 39% to 36%. Every point is a real survey reading, never a projection.

Live coral cover, percent by year

40%0%region avg 37%20142024
Two surveys
East Asian Seas average (GCRMN)
GCRMN reef surveys

What you will see

10 species across the dive sites here

Dive sites

What divers say

Richelieu in March with a whale shark sliding around the rock — I've chased that dive every year since.
— Repeat liveaboard guest

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.

Gear & getting wet

  • Basic kit

    • Mask and fins
    • BCD and regulator
    • 3mm full wetsuit · warm water
    • Dive computer

  • For specific sites

    • SMB · Richelieu Rock
    • Reef hook · Richelieu Rock