Hin Daeng / Hin Muang
Richelieu Rock · Thailand
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.
Conditions
Depth
5 to 40 m
Advanced depths
Current
Often strong
Can pick up on the edge
Visibility
10 to 15 m
Clearest in the calm season
Water
27 to 30°C
3mm tropical wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 27 | 27 | 28 | 28 | 28 | 27 | 27 | 27 | 27 | 27 | 28 | 27 |
| Vis (m) | 20 | 20 | 25 | 20 | 10 | 10 | 10 | 10 | 10 | 15 | 20 | 20 |
| Current | Moderate | Moderate | Moderate | Strong | Strong | Strong | Strong | Strong | Strong | Strong | Moderate | Moderate |
Your chances of seeing each animal
Oceanic manta ray
Last confirmed Apr 15, 2026 · 45 records
Very likely
Most dives
Giant trevally
Last confirmed Jan 3, 2026 · 2 records
Likely
About 6 in 10 dives
Leopard (zebra) shark
Expected
Known here, not yet in recent logs
Grey reef shark
Expected
Known here, not yet in recent logs
Schooling chevron barracuda
Expected
Known here, not yet in recent logs
Whale shark
Expected
Known here, not yet in recent logs
Gear