Turtle Ledge

The reef slopes gently rather than dropping away, and Scubago gives it about 25 m at its deepest. Most of the dive is spent well above that, swimming over the top of the coral instead of alongside it; Wikipedia's dive-site table gives an average depth of 15 m for Turtle Ridge, which is nearer to where the bottom time actually goes. The hard corals are the structure and the subject: multi-hued colonies across the shelf, with reef fish over them in quantity and variety.

The interest turns fine-grained as you work the shallower ground. Octopuses hold in the coral heads and nudibranchs move along the margins, so the second half of the dive tends to slow right down. Bottom times run long because there is no depth to spend, and the shallow finish means the safety stop happens over living coral rather than in blue water.