Sail Rock & Southwest Pinnacle
Thailand · Asia
Sail Rock, known locally as Hin Bai, rises from the Gulf of Thailand between Koh Tao and Koh Phangan and is widely regarded as the Gulf's premier dive site. A dramatic chimney runs through the rock allowing divers to ascend through a column of glassfish, while the surrounding walls are draped with seafans and patrolled by whale sharks from February through May. Southwest Pinnacle, a cluster of submerged peaks southwest of Koh Tao, draws schooling barracuda, trevally, and frequent whale shark sightings in the same season.
How this reef is doing
ⓘ How we measure thisReef state
Live science signals for this reef are still being gathered.
Coral cover
Fish life
Heat
Fishing
Open to fishing, and the water is busy.
Sources · Global Fishing Watch and reef gravity
What you will see
14 species across the dive sites here
Blue-spotted ribbontail ray
Seen 1 month ago
at Southwest Pinnacle
Least concern
Whale shark
Seen 6 months ago
at Southwest Pinnacle
Endangered
Great barracuda
Seen Jul 2025
at Southwest Pinnacle
Least concern
Anemonefish
Seen year round
at Samran Pinnacle
Least concern
Barrel Sponge
Seen year round
at Samran Pinnacle
Bigeye trevally
Seen year round
at Southwest Pinnacle
Brown Marbled Grouper
Seen year round
at Samran Pinnacle
Least concern
Chevron Barracuda
Seen year round
at Samran Pinnacle
Least concern
Fusiliers
Seen year round
at Southwest Pinnacle
Giant grouper
Seen year round
at Southwest Pinnacle
Giant Trevally
Seen year round
at Samran Pinnacle
Least concern
Moray eel
Seen year round
at Southwest Pinnacle
One-spotted Snapper
Seen year round
at Samran Pinnacle
Least concern
Yellowback Fusilier
Seen year round
at Samran Pinnacle
Least concern
