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Hotels, dive operators, gear, and how to get here are on the Richelieu Rock location page.
Overview
Two open-Andaman pinnacles about 500 m apart, 70 km southwest of Koh Lanta. Hin Daeng ('Red Rock') rises from roughly 50 m and is sheeted in red soft coral; Hin Muang ('Purple Rock') is Thailand's tallest submerged wall, dropping past 70 m and carpeted in purple soft coral. Oceanic mantas up to 4 m across circle the pinnacles to feed on the current, and whale sharks pass through from February to April. The exposed location draws strong current and has no surface marker, so every dive is a drift that ends mid-water under an SMB.
Briefing note
Inside Mu Ko Lanta National Park, usually closed mid-May to mid-October during the southwest monsoon. Exposed, deep, strong-current site - advanced certification and Nitrox recommended; surface conditions can deteriorate quickly.
What you'll see
6 species curated- seasonalOceanic manta rayPeak: Jan · Feb · Mar · Apr
- seasonalWhale sharkPeak: Feb · Mar · Apr
- year-roundLeopard (zebra) shark
- year-roundGrey reef shark
- year-roundSchooling chevron barracuda
- year-roundGiant trevally
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 27–29 °C | 20–30 m | moderate |
| Feb | 27–30 °C | 20–30 m | moderate |
| Mar | 28–30 °C | 25–30 m | moderate |
| Apr | 28–30 °C | 20–30 m | strong |
| May | 28–30 °C | 10–20 m | strong |
| Jun | 27–29 °C | 10–15 m | strong |
| Jul | 27–29 °C | 10–15 m | strong |
| Aug | 27–29 °C | 10–15 m | strong |
| Sep | 27–29 °C | 10–15 m | strong |
| Oct | 27–29 °C | 15–20 m | strong |
| Nov | 28–30 °C | 20–30 m | moderate |
| Dec | 27–29 °C | 20–30 m | moderate |
Season calendar
Peak season highlighted · current month outlined
Gear for this site
Beyond the basic kitNext step
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