Hairball

You go in from the boat and drop onto a gentle slope of black volcanic sand scattered with rocks, debris and thick algae. The site sits on a point, which draws nutrient-rich currents across it, and the current itself stays very mild, so the dive is worked at walking pace rather than swum. The productive band is roughly 8 to 18 m, and the slope carries on down to about 28 m if a guide follows something deeper.

There is no reef structure to navigate by, so the route is whatever the search turns up: patches of algae, half-buried rubble, sunken logs and single rocks are each checked in turn. Several frogfish species and unusually large seahorses are the standing draw, and the question on this slope is how many rather than whether. Visibility runs 5 to 20 m, so subjects are found close in and framed close in.

After dark the same slope is a different dive. Stargazers lie buried with their eyes turned up, cuttlefish and their egg clusters are out on the open sand, and decorator crabs and Spanish dancers appear that the daylight dive does not turn up. Because there is no coral to hold position against, buoyancy over the bottom is what keeps the sand out of the water column and the subject visible for everyone behind you in the group.