Lost Blue Hole

The hole opens in the sea floor as a circle about 100 ft (30 m) across with its perimeter rim at 40 ft (12 m). Boats put divers onto that rim, which is packed with hard corals, and the first part of the dive is a lap of the edge — jawfish, gobies, blennies and tobacco fish in the sand and rubble around it, with the blue of the shaft opening below.

Below the rim the hole falls to 200 ft (60 m), well past recreational limits, so any descent into it is a partial one against a turn depth agreed on the boat. Goatfish, snappers and sweetlips hold along the upper walls, nurse sharks and rays are regular inside the hole, and turtles pass through. Lobsters and soldierfish sit back in the shade, which is where a torch earns its place even in the middle of the day.

From May to early August blacknose sharks gather here to mate, and that is the one seasonal reason to time a visit rather than take the weather as it comes. Dives end back on the rim in 12 m, working the coral edge on the gas that is left, which makes the safety stop a shallow reef dive rather than a hang in open blue. Most of the interest is in the first half of the profile, so plan the deep part first.