Ghoubbet al-Kharab

The Crack, La Faille, is the shallow dive: a diagonal fissure covered in corals that divers can swim through, in places as little as 8 metres down. It sits on the plate boundary the cove straddles, and the geology is the point, lava rather than reef shelf, with the rift itself the feature you follow. It is easy enough water that all levels are taken on it, and it is the reason boats make the run to the western end of the gulf.

Beyond the cove the water narrows into the channel that joins the Ghoubbet to the Gulf of Tadjoura, and that is a different dive entirely. The channel is worked at 35 to 45 metres by advanced divers; the current there has a long record of violence and can run at more than 2 knots, and the cove behind it averages 205 metres deep. Lava tunnels run through the volcanic rock, and the macro life on the dark stone is worth the slow pass: seahorses, nudibranchs and other small subjects on the walls.

From late October to February whale sharks move into the Ghoubbet, and manta rays, schools of barracuda and other pelagic fish work the same water. November to January is the prime window, when conditions are most settled and the odds on a shark are best. The bay runs about 21 kilometres end to end, so a day here is a run between a handful of features rather than a stay on one mooring.