
Oceansub Estartit
Owner-led PADI centre on Carrer Salines in L'Estartit, capping each guide at 5-6 divers across the Illes Medes, Montgrí, and Cap de Begur.
Also known as: la Vaca
Wide 30 m through-tunnel under Meda Gran with three lit entrances, a habituated resident grouper, and a gorgonian wall on the north exit.
Last updated May 2026
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 drops to 45 metres for divers cleared for it; recreational groups turn back along the wall at 25-30 metres. On the return to the boat, two small caves and a chimney at 13 metres — the Rincon de la Vaca — extend the dive without re-deepening.

Illustration: Parc Natural del Montgrí, les Illes Medes i el Baix Ter — Generalitat de Catalunya
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 — the gorgonians draw the eye downward and the seabed sits at 45 metres. If the dive plan goes wall-deep, watch MOD on Nitrox before air becomes the limit. 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.
What makes this dive site stand out.
30 m passage with three entrances; sunlight reaches every section so the exit is visible from inside
Silhouette frames against the blue exit are the signature shot of the Medes rotation
A large dusky grouper hovers near the south entrance; decades of guided diving have shaped behaviour
Tunnel works at 12-22 m for OW; north wall drops to 35-45 m for AOW on the same mooring
Two small caves plus a chimney at 13 m near the boat extend the dive without re-deepening
42.0474°N, 3.2264°E
Book a guided dive at this site.

Owner-led PADI centre on Carrer Salines in L'Estartit, capping each guide at 5-6 divers across the Illes Medes, Montgrí, and Cap de Begur.

Family-run PADI 5 Star Resort and SSI centre in L'Estartit since 1990, with two 30-diver boats running hydraulic lifts to the Illes Medes reserve.

Family-run PADI centre in L'Estartit, run by Peter and Jacqueline Lane for nearly 40 years, with PADI Green Star and four other environmental credentials.

PADI 5 Star centre on L'Estartit seafront with stay-and-dive packages, four daily boat dives between Illes Medes and Montgrí, plus tec diving.

Family-run hotel and dive centre in L'Estartit since 1985, with two dedicated boats and four daily departures to the Illes Medes reserve.

Long-running L'Estartit dive centre (founded 1969) running a four-boat fleet to the Illes Medes reserve and Montgri coast, with SSI training and a strong family/snorkel programme.

SSI Diamond Instructor Center in L'Estartit, authorized Illes Medes operator since 2008. Full spectrum from try dives to cave and technical diving.

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Easy through the tunnel. Moderate to advanced for the full dive including the north wall.
Parc Natural del Montgri, les Illes Medes i el Baix Ter
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