Punta Restinga

The mooring drops you at 11 metres onto the edge of a submarine lava tongue extending from Spain's southernmost point. Four named routes depart from the same buoy, and which one you take depends on conditions and what your guide reads at the surface. The typical approach for El Arco follows a flat run of lava and calcareous algae out to 30 metres before the terrain suddenly drops to a rock arch at 40m — its surface colonised by black coral. Shallower routes through Los Cañones offer canyon navigation and crevice hunting at recreational depths. Stingrays cross sandy platforms between volcanic formations, trumpetfish trail larger fish in open water above, and large groupers station themselves at every depth level. The terrain shifts every few fin kicks: cliffs, drop-offs, caves and open plateaus in quick succession.

A single mooring giving access to the full spectrum of recreational diving is unusual. Beginners run the shallow canyons with no current pressure. AOW divers head for the vertical veril or the deep arch with its overhead section. The volcanic seabed has a quality that the 2011-2012 eruption renewal reinforced: since then, marine life density climbed, and the groupers here are among the larger specimens found in the Canaries.

The geographic position matters. This is the southernmost dive site in Spain, on an island in the middle of the Atlantic. Visibility at 30 metres is unremarkable. On the best days it reaches 40.

Current is the main variable. Centres rate it medium to high on average, but individual dives range from barely noticeable to demanding. Always ask which route fits the day's conditions before you leave the dock. For El Arco, carry a torch — the arch is an overhead environment, and crevices on the way hold moray eels and lobsters invisible without light. Fire worms are common throughout La Restinga sites. They look soft. They are not — contact embeds bristles in skin. An SMB is standard kit; drift diving is not permitted and you must return to the mooring. If planning the deep route, Nitrox is worth the extra cost at this depth.