Unicorn Wreck
A steel cargo ship of about 60 m, also known as the Hishidaiya Maru, that sank around 1989 and lies upright offshore of Koh Tao. Its cargo was reportedly pet food rather than the declared tuna, hence the 'dog food wreck' nickname. This is technical depth only: the top of the bow is around 38 m and the seabed around 50 m, visibility is often poor and silty, and nets are reported on the wreck. Giant groupers, barracuda and trevally are seen around it.
depth: 38–50 m