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.
Facts
- Region: Thailand – Koh Tao & Samui
- Area: Koh Tao west & north
- Depth: 38–50 m
- Level: advanced
- Current: moderate
- Type: wreck
- Coordinates: 10.1617, 99.8488 (approximate)
- Highlights: wreck, giant grouper, barracuda, trevally, snapper, fusilier, blue-spotted stingray, lionfish
- Unverified: Depth and position: Thai Wreck Diver gives a Navy GPS north of Mango Bay with the seabed at ~50 m, while Big Blue describes it as west of Koh Tao with the deck at ~30 m and the seabed at 34–36 m.
- Tips: Technical depth only (trimix/deco training); penetration is not advised – a silt-out is likely.