HTMS Sattakut

The HTMS Sattakut is an advanced wreck dive off the western coast of Koh Tao, where a decommissioned Thai Navy vessel was intentionally sunk in 2011 to create the island's premier artificial reef and wreck diving attraction. Lying at thirty meters depth, this former US-built landing craft ship provides Koh Tao with a substantial wreck dive that has rapidly become one of the island's most popular advanced sites. The vessel sits upright on the sandy bottom, its military profile creating an impressive underwater silhouette. At approximately fifty meters in length, the Sattakut is large enough to offer extensive exploration but compact enough to circumnavigate during a single dive at depth. The ship was thoroughly prepared for diver access, with hazardous materials removed and strategic openings cut to facilitate safe penetration. Marine colonization has been rapid in the warm Gulf waters. Soft corals, barnacles, and sponges coat the hull surfaces, while hard coral recruitment builds reef structure on the metalwork. Fish have adopted the wreck enthusiastically, with schools of batfish, snappers, and fusiliers orbiting the superstructure. Large groupers inhabit the internal spaces, and the wreck's crevices harbor lionfish, moray eels, and various invertebrates. The thirty-meter depth demands advanced certification, proper gas management, and experience with the physiological effects of depth in cold water. Bottom time at this depth is limited on recreational gas mixes, and many divers opt for enriched air to extend their time on the wreck. Interior penetration through the prepared access points offers atmospheric diving for those with wreck diving certification. The HTMS Sattakut has transformed Koh Tao's diving portfolio by adding a genuine wreck dive to the island's already impressive natural sites. The combination of accessible wreck structure, growing marine community, and the thirty-meter depth creates an advanced diving experience that gives Koh Tao divers a compelling reason to pursue further training and certifications.