Bajo de Piles II

The centre likens the bajo to a loaf of bread: a long rocky barra lying in open water in the middle of the reserve, with sand, gravel and posidonia around its base. A boat from Puerto de Cabo de Palos takes divers out, and the transfer is part of the dive's price. The top climbs to about 10m, the plateau is flat at 20m and the flanks drop to 27-28m, with the length quoted anywhere from 75 to 110m. Dusky groupers of every size live in the rock, false cod and morays use the holes and cracks, damselfish gather in clouds over the plateau and two-banded bream cruise in loose groups. Ornate and rainbow wrasse are among the regulars, and nudibranchs sit on the walls.

The draw is the vertical spread of one rock: a single ridge holds shallow, middle and deeper routes. Barracuda gather close to the bajo, and the groupers and false cod keep to the rock at every depth. In autumn, schools of bogue are reported to bring bullet tuna, skipjack and Atlantic bonito through the same water.

Surface water reaches 24-28C in July and August, but from about 25m down it holds 15-18C under a sharp thermocline, so pick the suit for the lower number. Spring and autumn run 18-24C at the surface and 15-20C at depth, and in January and February the whole column sits at 13-15C. Visibility is 15-20m in summer, 20-30m in spring and autumn and drops to 5-10m after storms.

The centre asks for a valid certification, valid insurance and a signed health declaration on the day of the dive, and handles the authorisation for the reserve. Nothing shelters the ridge from open water, and the current runs from mild to strong, stronger in November and December. A running current brings the barracuda in to hunt, which makes it the best day for them and the day to agree the route and the return leg with the guide before descending. When it blows hard, the area falls back on Bajo de Testa, the more sheltered bajo.