HTMS Chang Wreck

Koh Chang · Gulf of Thailand · Thailand

The HTMS Chang is a monumental wreck dive lying on the sandy seabed off the western coast of Koh Chang in Trat Province, eastern Thailand. This former Royal Thai Navy landing craft, measuring over 100 meters in length, was deliberately sunk in November 2012 to create the largest artificial reef in the Gulf of Thailand and serve as a flagship dive attraction for the Koh Chang archipelago. Descending the mooring line, the sheer scale of the wreck takes your breath away. The vessel sits upright on the bottom at 30 meters, with the top of the superstructure reaching up to about 12 meters, creating a massive structure that you cannot fully explore in a single dive. The bridge and upper deck structures are encrusted with soft corals, barnacles, and anemones that have colonized the metal surfaces in the years since sinking. Schools of batfish orbit the mast and upper works in enormous, lazy formations that part and reform around ascending divers. I was struck by how quickly marine life has adopted this artificial structure. Giant groupers lurk in the engine room, their dark shapes visible through open hatches. Yellowtail snapper form dense schools along the hull, and barracuda hold station in the current off the bow. Lionfish claim every sheltered corner and overhang, their venomous fins splayed in territorial display. The wreck penetration opportunities are extensive and well-prepared. The Thai Navy removed hazardous materials and cut additional access points before sinking, creating safe routes through the cargo holds, engine room, and bridge. Swimming through the cavernous interior of the cargo bay, light filtering through hatch openings above, is an experience that ranks with the finest wreck dives in Southeast Asia. The wreck is evolving year by year as coral colonization accelerates and the marine ecosystem around it matures into a thriving reef community.