Diving Sail Rock in Koh Tao, Thailand

I dove Sail Rock in August 2026 with Big Blue Diving, by boat out of Koh Tao, Thailand.

We dove it twice in one day, and the second dive finished on the largest amberjack bait ball I have ever seen.

Sail Rock is a giant rock protruding out of the ocean, and it pulls in an insane amount of life.

It sits out in the gulf between Koh Tao and Koh Phangan, so it is a longer boat ride than the sites just off the island.

The Chimney

We dropped down directly on top of the Chimney.

I would not really call it a swim-through.

It is more of a drop-down that starts at 30 feet (9 m) and descends all the way to 60 feet (18 m).

The Dive

We did two dives at Sail Rock.

Towards the end of the second dive, our guide put us directly on top of the largest amberjack bait ball I have ever seen in my life.

My Garmin Descent MK3i logged a max depth of 82 feet (25 m) and an average depth of 43 feet (13.1 m).

Sail Rock is also covered in anemones.

They blanket the rock so completely that you can barely find bare stone under them.

I do not think I saw a single orange clownfish anywhere in Thailand.

The site is known to get whale sharks, and I did not see one on either dive.

Getting to Sail Rock

Sail Rock sits on its own out in the gulf, so every trip to it is a boat day from one of the three islands.

I went from Koh Tao with Big Blue Diving.

Koh Tao is the longest crossing of the three, because Sail Rock is closer to Koh Phangan.

What I was told on the island is that the longer ride is worth taking.

Boats out of Koh Tao do three dives in the day, while most Koh Phangan trips do two at Sail Rock and head back.

I did not dive it from Koh Phangan or Koh Samui, so the numbers below come from the operators who run those trips rather than from my own experience.

From Koh Tao: Big Blue publishes 3,900 THB, around 107 US dollars, for a three dive day that includes the guide, tanks, weights, breakfast and lunch.

From Koh Phangan: roughly an hour on the water, the shortest crossing of the three. Boats out of Chaloklum Pier tend to leave around 8am and are back by early afternoon. Sail Rock Divers and The Divers Boat both price a two dive trip between about 2,900 and 3,200 THB, or roughly 80 to 90 US dollars.

From Koh Samui: about 50 minutes from the pier, with hotel pickup around an hour before that. Silent Divers and Discovery Divers both run it, and advertised two dive prices range from about 2,250 THB to 4,650 THB, roughly 62 to 128 US dollars, depending on whether transfers and gear are included.

That puts Koh Tao at about 1,300 THB a dive against 1,450 to 1,600 from Koh Phangan, so the higher sticker price is the cheaper day in the water.

Most operators on all three islands ask for an Open Water certification as a minimum.

Dive Conditions

Water temperature averaged 86°F (30°C).