La Vaca

Three openings in the rock face at the south flank of Meda Gran, all converging into a single passage that cuts through the island. The resident grouper is usually waiting somewhere near the entrance, a metre-long fish that ignores divers more than it reacts to them. The tunnel runs 30 metres north, around 5 metres wide, broken inside by rock pillars and short partial walls. Light enters from the three south entrances and from openings above, so the passage never goes dark. Swim toward the blue rectangle of the north exit at 22 metres, where the tunnel opens onto a vertical wall thick with red gorgonian fans. Schools of brown meagre and gilt-head bream hold station along the wall edge. Below, the rock-block platform keeps dropping, deeper than the park's guidance for recreational dives; the guide sets how far the group goes along the wall. On the return to the boat, the Rincon de la Vaca at 13 metres has two small caves and a chimney. Unlike the lit tunnel, the caves are dark and narrower, and the Park says visiting them takes more experience; the guide decides whether the group goes in.

Natural light is the headline. The tunnel's three entrances and the geometry of the passage mean sunlight reaches every section, and the exit reads as a blue frame from inside. The signature shot of the Medes rotation, silhouette diver against the blue rectangle, is taken here. The transition compresses two dive characters into one profile: enclosed rock with red coral, sponges and bryozoans on the walls, then open water and a gorgonian-covered drop on the north side. The resident grouper sits somewhere on that boundary. Forum reports from regulars are honest about the fish: it has been around long enough to associate divers with attention rather than threat, which is striking on a first visit and a little ambiguous on later ones.

Buoyancy control matters inside the tunnel. Sediment on the floor rises fast if a fin clips it, and the encrusting life on the walls and ceiling is fragile. Hover, do not settle. On the north wall, depth creeps up without warning because the gorgonians draw the eye downward. The guide sets the depth for the group and the dive follows that plan. Visibility varies more than centre marketing suggests. Calm summer produces 15-25 metres; after storms or Ter-river runoff it can drop below 5 metres, and the 2004 forum trip reports include both extremes from the same diver. The boat run from L'Estartit is short but exposed to ground swell outside the summer flat-calm windows.