La Catedral

The dive opens in a large cave, with a siphon near its roof at about 10 metres. From there the route moves through a succession of immense vaults, and the light changes from one chamber to the next. Outside the cave the walls fall to 45-50 metres, and on the outer drop, with luck, an amberjack or a barracuda cruises past. Closer in, the life is small: bogue, ornate wrasse and comber over the rock, sea urchins, nudibranchs and shrimp, with moray eels and octopus in the crevices. The dive is estimated at 45 minutes.

Depth depends on how much of the massif the route takes in. The cave start and its siphon sit near 10 metres, one published average for the dive is 17 metres, and the massif is published at 6 to 40 metres with the outer walls dropping on to 45-50. By depth alone, anything below 18 metres is Advanced ground, and the operators ask for Advanced Open Water for the dive as a whole.

The formation stands more than 30 metres tall, one eroded mass of volcanic rock twisted into near-gothic shapes and riddled with caves, vaults, arches, passages and near-vertical dykes, which is where the cathedral name comes from. Between the caves, beams of light and the shadows around them are what pull underwater photographers to the rock.

Carry a torch for the shadowed chambers. The dive only goes ahead when sea and wind allow, so availability cannot be guaranteed. In a choppy northern sea, the small RIB may bring seasickness and make gearing up awkward.