Azul House Reef

You work out along the reef over sand and rock, the ground stepping down to 18 metres at its deepest, so the whole dive sits comfortably inside no-decompression limits. The bottom topography changes as you go: patches of sand, then broken volcanic rock, then isolated blocks of coral standing clear of it. Barracuda and groupers are the fish you notice at that stage; the smaller things are in the rock.

The caves are what the site is known for. They are cut into the volcanic rock rather than built by coral, and they punctuate a route that otherwise runs over open bottom. Frogfish, seahorses and garden eels are listed here alongside octopus, cuttlefish and morays, so the second half of a dive is usually spent slowly, looking into holes rather than covering ground. Because the maximum is 18 metres, a diver on their first dives and an experienced one can be taken down on the same tank.