Shark Island

Shark Island sits 300 metres off Koh Tao’s southeastern tip — a small, uninhabited granite outcrop named for the dorsal fin silhouette it cuts above the waterline when viewed from the south. Underwater, giant boulder formations slope from just below the surface down to sandy patches and rocky ledges at 25–28 metres, with a layout that naturally lends itself to a circular route and rewards repeat visits. Currents run here with some regularity, drawing schooling barracuda, trevally, and snapper into the water column and making it one of the more dynamic sites on the island.

Marine life is diverse across the full depth range — moray eels, blue spotted ribbontail rays, hawksbill turtles, and butterflyfish through the boulder sections; nudibranch species on the eastern side; soft coral gardens along the southern end; and occasional whale shark sightings in the blue. Best suited to Advanced Open Water divers, particularly when current is running, though the shallower sections are manageable for Open Water divers in calm conditions.