HTMS Suphairin (313)

The HTMS Suphairin, formerly hull number 313, is a decommissioned Thai Navy vessel that was deliberately scuttled to create an artificial reef and a new wreck diving site for Koh Tao. At over 100 metres long, it’s one of the largest structures divers will encounter around the island, and the scale alone makes it a different kind of dive from the island’s natural reef sites.

The wreck sits upright on a sandy bottom, which makes orientation straightforward even for divers new to wreck diving. Several open compartments and passageways allow for genuine swim-through exploration, while the exterior decks and structures are accessible to less experienced divers who prefer to stay outside the hull.

Marine life has colonised the wreck steadily since it was sunk. Schools of fusiliers and batfish move around the superstructure, while smaller reef fish have taken up residence in the nooks created by the ship’s structure. The wreck also attracts the kind of macro life that favours artificial structure — nudibranchs and small crustaceans are a regular find for divers who take the time to look closely.

Because of its size and depth range, the HTMS Suphairin rewards multiple dives. A single visit barely scratches the surface of what the wreck has to offer, and many divers return to explore different sections on subsequent trips.