HTMS Chang wreck

The HTMS Chang Wreck near Koh Chang is one of Thailand's most impressive artificial reef dives, a massive former Thai Navy landing craft ship intentionally sunk in 2012 to create a diving attraction and marine habitat in the eastern Gulf of Thailand. At over one hundred meters in length and resting at thirty meters depth, this is one of the largest diveable wrecks in Thai waters and the centerpiece of Koh Chang's diving scene. The HTMS Chang was decommissioned after decades of naval service and prepared for its new role as an artificial reef. The vessel sits upright on a sandy bottom, its enormous hull and superstructure creating a dramatic underwater presence that emerges from the Gulf's green water with imposing scale. The bridge, radar platforms, gun mounts, and deck equipment retain their military character, creating an exploration experience that feels like visiting a submerged naval installation. Marine colonization has been enthusiastic in the warm Gulf waters. The hull surfaces are increasingly covered with soft corals, sponges, and hard coral recruits that will eventually transform the vessel into a living reef. Fish have adopted the wreck in impressive numbers, with enormous schools of batfish being the most iconic residents. Snappers, groupers, and barracuda are all well established, and the wreck's vast internal spaces concentrate marine life in atmospheric overhead environments. The thirty-meter depth demands advanced certification and careful dive planning. The wreck's length means a complete exterior tour at depth is challenging within recreational gas limits, and most divers focus on specific sections during each visit. Interior penetration through prepared access points offers exploration of the bridge, engine room, and crew quarters for appropriately trained divers. The HTMS Chang has transformed Koh Chang from a secondary diving destination into a legitimate wreck diving hotspot. The combination of enormous scale, growing marine community, and the dramatic setting off Thailand's second-largest island creates a wreck dive that deserves its place among the finest in Southeast Asia.