Stonehenge

You drop onto the top of the dome at about 6 m, into a carpet of soft coral in oranges, yellows, blues and purples, with large sea fans on the flanks. Outcrops of rock on the southeastern side are the ones that gave the site its name. The rock falls to a sandy area at 12 to 18 m and the deepest ground is around 25 m, so the whole dive fits inside an ordinary no-stop profile.

Work around the base and back up. Leopard sharks rest on the sandy patches, moray eels watch from the crevices, including honeycomb morays and some enormous giants, and schools of snapper and fusilier swirl around the rocks with barracuda and trevally passing outside them. Brown-marbled groupers hold station on the rock, and tiger-tail seahorses and tomato anemonefish reward a slow look at the coral.

This is a photographer's site. The light plays off the vertical formations, and going slowly and looking up is what gives you the silhouettes. Current is the one thing to watch: it runs mild to strong and can be unpredictable, changing direction between the pinnacles, so agree with your guide which side of the rock you finish on before you go in.