Carall Bernat

Large blocks of rock and steep walls ring this south-eastern corner of the Illes Medes, and the dive follows them from the mooring buoy. Gorgonians cover the walls, groupers sit among the blocks, and morays and sea bream work the crevices; arches break the wall in places and deeper down it gives way to platforms and canyons.

The water sets the route. With no current the whole rock can be circled, a loop that reaches about 30 m; with current, the wall and the large blocks are the place to stay, and the far side of the rock offers a shallower option at 15 to 18 m. Between the rock and Tasco Gros runs a channel only 5 m deep, where nudibranchs, groupers and everything between turn up. Looking out into the blue pays off too, since tuna, bonito, sunfish and amberjack pass.

This southern zone of the archipelago holds the highest concentration of groupers in these waters, large resident fish close to the wall. They share it with gorgonian-covered rock where Axinella polypoides and the trumpet shell Charonia lampas are protected and the red gorgonian is fragile, so careful buoyancy matters as much as the route.

Current is the other half of the character. It carries eagle rays, barracuda and tuna past the outer part of the zone, and eagle rays are frequent there in summer. The same flow is what makes the dive demanding when it picks up.

Ask the centre at booking which route it plans for the day and what the current was doing at the buoy on the previous dives; on a strong day expect the wall and blocks, not the full circuit. Nitrox 32% suits the usual profile, and a surface marker buoy goes in the kit. Begin the return to the line early, because the flow can rise just when you head back.