Túnel de la Ferriola

The boat moors in the sheltered interior of Cala Ferriola, which means calm water for gearing up even when the open coast is choppy. Descend along the islet wall to a crevice at 12 metres. This is the tunnel entrance. The passage runs 30 metres northeast, wide enough to swim through relaxed and in good trim, with both exits visible from the moment you enter. Red coral and sponges cover the walls in colour that pops under a torch. At 25 metres, the tunnel opens to open water. Ahead, a canyon runs northeast to a sandy bottom at 29 metres where lobsters settle among the rocks. The return follows the outer face of the islet upward through 5 to 10 metres, past moray eels in the crevices and octopus in the holes, back to the boat.

La Ferriola is the most accessible tunnel dive in the Medes and Montgrí park area. La Vaca is deeper and more dramatic; La Pedrosa is longer with its chimney. This site suits those taking their first steps into overhead environments. The wide, straight passage never goes dark. A diver who hesitates at La Pedrosa's 70-metre length or La Vaca's 45-metre north wall will swim through La Ferriola and feel competent. The lobsters are what divers remember. Many in season, concentrated on the sandy canyon floor and in the tunnel crevices. No gorgonian walls here, unlike most Medes sites. The tunnel character is red coral and invertebrates on rock.

Fin technique matters inside the tunnel. The floor is sandy and a careless kick throws up a silt cloud that reduces visibility for everyone behind you. Horizontal trim and short, controlled strokes keep the water clear. Midday is the best time if photography is the goal: backlight enters both tunnel mouths simultaneously. The 29-metre canyon is optional. OW divers on a guided first tunnel dive can stay shallower and skip it. Nitrox 32 is available and worth it if you want time at the canyon floor. Boat travel from L'Estartit is 25 minutes each way, slightly longer than the Medes island sites.