A lagoon with a back door
The Inland Sea is one of the odd corners of the Maltese islands. A circle of water sits behind a ridge of rock, with small fishing boats tied up on its edge and the cliffs standing around it. The only way out to the open sea is a tunnel through the rock, a dark slot that boatmen thread through in good weather.
Divers use the same tunnel. The dive starts in the lagoon, passes through the passage and emerges on the outside, where the sea is deeper and the view opens. For many people it is the most memorable thing about the site: leaving a calm, almost domestic stretch of water for the Mediterranean in the space of a few minutes.
Inside the lagoon
The bottom of the lagoon is mostly pebbles and rocks, and it is fairly shallow. This is not the part of the dive that attracts photographers. It is a settling-in stage, giving you time to check weights, trim and air before you commit to the passage.
Take your time. Swimming slowly and watching the bottom shows small fish among the stones, and the contrast with the tunnel makes the later part of the dive feel larger. It is also a good place to check that your buddy is comfortable.
Through the tunnel
The tunnel itself is short and bright enough that most divers feel at ease. Even so, it is an overhead environment, so keep to the guide’s line, avoid touching the walls and move one behind the other if the passage narrows. Swell can push divers around in the tunnel, and boat traffic is a concern on days when fishermen are out.
On the way through, the light changes. Blue enters from ahead, the walls take on a green cast, and you arrive at the outer opening with a clear sense that the sea has changed character.
The outside
As you exit towards open sea, the floor drops away in a series of shelves to a depth of up to 35 metres. Those shelves are the main feature of the outer dive: a series of terraces where rock and sand alternate, each one a little deeper than the last. The plan for the day determines how far down you go, and a good guide will pick a depth that keeps you within limits for your qualification.
Open water here has more life than the lagoon, and you will see fish that prefer rocky terraces. Keep an eye on gas and on the group, and let the guide decide when to turn. The return to the tunnel is easier if you have kept track of where it lies.
The Dwejra setting
The Inland Sea sits in one of the most scenic stretches of the Gozo coast. Cliffs, salt pans and flat rock platforms surround it, and the Azure Window, which stood nearby until it collapsed in 2017, once drew crowds to the same spot. The collapse changed the shape of the shore but not the tunnel, which remains the main attraction for boats and divers.
Even without diving, the lagoon rewards a visit. Boat trips run through the tunnel when conditions allow, giving non-divers a version of the same passage, and the area has cafes and stalls that open in the season.
Planning the day
Book with a licensed dive centre, and ask them to explain the entry, the tunnel route and the exit before you go. Bring certification, logbook and a torch, and wear an exposure suit suited to the season. The area can be windy, so a warm layer for the surface interval is useful.
Check sea conditions on the day. Dive centres on Gozo often swap sites at short notice, and a cancelled tunnel dive is a sensible decision, not a failure. If the western sea is rough, ask about alternatives on the sheltered side of the island.
The Blue Hole lies close by and makes a natural pairing, since both sites share the same stretch of coast. Many divers do the lagoon in the morning and the Blue Hole after lunch, or split them across two days with a rest between.
After the dive, a short walk around the rocks and a coffee in the village of San Lawrenz is an easy way to finish.
