Hin Daeng Wall

Nothing above water suggests what is below. Hin Daeng shows only bare rock at the surface, and the pinnacle beneath it falls away from about 5 metres to past 40, with dives planned as deep diving in the 25 to 40 metre band. You drop in beside the rock and work the drop-off rather than covering ground, with healthy soft corals in shades of red on the walls the whole way along.

Current can be strong here, and the practical answer underwater is to pick the leeward side, where the boulder walls give plenty of shelter. From there the dive is about watching the blue as much as the rock. Grey reef sharks and leopard sharks patrol the deeper water, and one of the most striking sights on the site is a silver wall of trevally cruising past.

Manta rays are what Hin Daeng is famous for, and whale sharks turn up on the same walls far less predictably. Visibility runs between 15 and 40 metres and is usually in the 20 to 30 metre range, dropping only during the monsoon season, and the water sits at 27 to 30°C. The site lies within Thailand's Mu Koh Lanta National Marine Park, and plenty of small-scale action goes on among the soft corals for divers who look closely.