Sail Rock
Hin Bai · between Koh Tao & Koh Phangan
Sail Rock - Hin Bai to Thai boat crews - is the one pinnacle that breaks the surface. It stands alone in open water between Koh Tao and Koh Phangan: a lump of granite barely the size of a fishing boat above the waterline, and a cathedral beneath it.
Its walls drop almost vertically to around thirty metres before the seabed slopes away into the dark. Because it sits far from any reef, Sail Rock works like a magnet - chevron barracuda wind into slow tornadoes, bigeye trevally hunt in shimmering walls, and snapper and fusiliers crowd every ledge. The site's signature is The Chimney, a vertical swim-through that swallows divers at eighteen metres and releases them, blinking, into the light at six.
Things to see
Getting there
Reached on a full-day trip from Koh Tao. The Chimney swim-through calls for confident buoyancy and is best kept for experienced divers.
Whale sharks are seasonal and never guaranteed.
Dive this site with us
Hand-picked PADI courses based on this article.
Advanced Open Water
Advance to 30m depth with the PADI Advanced Open Water course in Koh Tao. 2 days, 5 adventure dives, deep diving and navigation. ฿10,000 with Siam Scuba.
View courseDeep Diving
Dive deeper safely in Koh Tao with the PADI Deep Diver specialty. 4 dives down to 40m, including Chumphon Pinnacle and Sail Rock with Siam Scuba.
View courseDive Sail Rock with Siam Scuba
Small groups, private dive boats, and instructors who know every metre of this site.
Book a fun diveRelated reading
Complete Guide to the Best Dive Sites on Koh Tao
From the famous HTMS Sattakut wreck to the legendary Sail Rock — here's everything you need to know about diving on Koh Tao.
When Is the Best Time to Dive Koh Tao? Month-by-Month Conditions and Wildlife Guide
Honest month-by-month guide to diving conditions on Koh Tao - water temp, visibility, sea state, weather, and which months actually have the worst diving.