Tremiti Islands

The diving is small-scale and close in. The centres are on San Domino and the boats are small, so a site is minutes away rather than a crossing, and the day is usually two dives with the surface interval back at the harbour. Limestone is the whole story underwater: undercut walls, arches and a coastline drilled through with caves and cavern mouths, several of them shallow enough that daylight still reaches well inside, with Grotta delle Viole lit through an opening in its roof.

Cavern work is the signature. Architiello is a rock arch off San Domino swum through at about 12 m, and Grotta del Bue Marino runs back far enough that divers can surface in an air chamber inside it. The shallower passages suit anyone with settled buoyancy, while the deeper caverns want Advanced and a light. The Padre Pio statue stands on a submerged rock at 14 m, shallow enough for a long bottom time, and below the sunlit band on the walls the gorgonians and yellow cup coral take over the rock completely.

This suits newer divers, photographers and anyone who likes overhead structure without technical commitment. The archipelago has been a marine reserve since 1989, but the interest is structure rather than big animals, and there is no drift diving; night dives are worth booking, since the shallow rock stays busy after dark. Time it carefully, though. Operators run roughly April to October, the islands wind down outside that, and Adriatic weather can turn a settled forecast into a cancelled day.