The Tremiti Islands — San Domino, San Nicola, Capraia, and Pianosa — float 22km off the Gargano coast in water so clear the Adriatic forgets it's supposed to be murky. Visibility regularly exceeds 30 meters and can reach 40m in late summer — numbers you associate with tropical diving, not a sea between Italy and Croatia. The marine reserve (established 1989) has produced results: enormous groupers (cernie) that cruise the boulder fields at 15m, gorgonian fans (paramuricea clavata) covering walls from 25-40m in orange and red, schools of amberjack and barracuda, and underwater caves where lobsters wave their antennae at your torch. This is the best diving on the Italian Adriatic — and one of the best in the entire Mediterranean. Gargano guide → · Puglia →
Plan my Tremiti trip →Secca di Punta Secca (San Domino): A submerged reef from 8m to 40m+. The upper section has boulder fields with groupers and moray eels in every crevice. Below 25m: gorgonian fans covering the wall. The signature Tremiti dive. Grotta delle Viole (San Domino): An underwater cave accessible at 10m depth with violet-colored sponges lining the ceiling — the light filtering through the entrance creates a purple glow. Relitto del Lombardo (San Domino): A 19th-century paddle steamer wreck at 12-18m — encrusted in marine life, easy penetration. Architiello di San Domino: A natural rock arch at 6m that frames the blue beyond — swim through it for the most photogenic underwater moment on the Adriatic. Capraia walls: The uninhabited island's northern face drops vertically from the surface to 50m — pristine wall diving with no boat traffic.
Dive centers: Tremiti Diving Center (San Domino — the established operator, PADI/SSI courses), Marlin Tremiti. Single dive: €40-55. Discovery dive (beginners): €60-75. Night dive: €50-65. Getting there: Ferry from Vieste (50min, €20-25 return) or Termoli (1h, €20). Helicopter from Foggia (15min, seasonal — expensive but unforgettable approach). Stay: San Domino (Hotel Kyrie €90-140, Hotel Gabbiano €80-120 — limited options, book ahead). Day trip possible from Vieste but staying 2-3 nights is better for multiple dives. Season: diving April-November. Best visibility: July-September. Water temp: 16-26°C (wetsuit needed year-round, 5mm spring/autumn, 3mm summer). Combine with: Gargano (Foresta Umbra, Vieste, Monte Sant'Angelo), Puglia coast.