Inland Sea Tunnel
Depth is the range from the top of the site to its usual maximum; "recommended cert" is the mainstream-agency level operators usually ask for, not a legal rule. Currents and visibility change daily — treat everything here as planning ranges.
The Inland Sea is a pebble-ringed lagoon sealed off by Gozo's cliffs, connected to open water only through a narrow slot a boat's width across — and divers ride that geology like a corridor into another world. The tunnel runs about 80 m, deepening as it goes, its final frame a burning blue rectangle that ranks among diving's great doorways. Outside, walls drop past 40 m into cobalt water where amberjack and dentex sometimes patrol. The return swim aims back at a keyhole of daylight. Timed between tour boats and swell, it is a short dive that stays in memory for years.
The moment you come for: The 80 m tunnel, the blue exit frame, big walls beyond the cliff
Topography: An 80-meter natural tunnel through the cliff, floor stepping from lagoon shallows down to about 26 m at the sea exit, opening onto steep walls
Entry: Enter the shallow lagoon by the fishermen's boat huts at Dwejra and follow the tunnel seaward — small tour boats use the same passage, so depth discipline and listening for engines matter.
Know before you splash
Hazards: Boat traffic in the tunnel overhead, darkness mid-passage, and swell funneling through in unsettled weather.
Conservation: Shared, protected space at Dwejra — give the tour boats the surface layer and the tunnel walls their fragile growth.
For photographers
Wide angle: ★★★★★ · Macro: ★☆☆☆☆ — editors' 1–5 rating of what this site gives each style of shooting