Diving Shark Island in Koh Tao, Thailand

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

It was the last dive of the day, straight after two dives at Sail Rock.

It sits about 3 miles (4 km) southeast of Mae Haad pier, the closest of the sites I dived.

That short run is why it often gets used as the last dive of a longer day.

Big Blue put it at the end of their Sail Rock trip, which is exactly how I dived it.

The Island

Shark Island is a small uninhabited islet off the southeast coast of Koh Tao.

It is named for its resemblance to a dorsal fin, and for its reputation as a hotspot for reef sharks.

The site splits into two experiences.

One side is a shallow coral garden suited to beginners, the other a deeper boulder slope for more experienced divers.

Due south and deeper again lies the MV Trident, an ex German coastguard vessel sunk in September 2010 at 36 metres.

That area often sees strong current, which combined with the depth puts it out of reach for most recreational divers.

The Dive

My Garmin logged a max depth of 63 feet (19.3 m) and an average of 29 feet (8.9 m) across 53 minutes.

That makes it the shallowest and longest of my Koh Tao dives.

I did not see a single shark.

Dive Conditions

Visibility on this dive ran around 60 feet (18 m), lower than it typically is at Shark Island.

Water temperature was 86°F (30°C).