La Amatista

The boat moors below the Mirador de la Amatista — the clifftop viewpoint that hikers photograph from above. Descending to 5-14 metres, you find a rocky shelf cut by volcanic canyons running parallel to the coast. Groupers occupy the shelf edges and corvinas press back into the canyon shadows. Between the rock outcrops, Posidonia oceanica meadows spread across the sand, and standing upright in the seagrass are the nacras — giant fan mussels that can reach 80cm, their shells partially visible above the grass canopy. Conger eels peer from crevices in the volcanic rock while cuttlefish hover over the sand patches separating the two habitats. The shallow depth gives you a full hour to cover both without hurrying.

La Amatista is the nacra dive of Cabo de Gata. Pinna nobilis — the Mediterranean's largest bivalve — has suffered catastrophic population collapse across its range since 2016, driven by a protozoan parasite. Surviving colonies have become conservation priorities, and the specimens here are among the most accessible in the park. Seeing them anchored upright in the Posidonia like organic sculptures is an encounter without equivalent at the neighbouring sites. The viewpoint above adds a dimension most dive sites lack: the same volcanic geology that tourists photograph from the cliff trail, you are exploring from the inside.

The nacras are critically endangered — do not touch them, and control your buoyancy carefully over the Posidonia meadows. Fin kicks stir sediment and can damage both the seagrass and the mussels embedded in it. The cliffs above have no shore entry, so this is strictly a boat dive. Four centres across La Isleta and San Jose include La Amatista in their rotation. At 5-14 metres maximum, this pairs well as a first or second dive of the day alongside a deeper site.