Mediterranean · Italy
Tremiti Islands
A bronze Padre Pio stands on a submerged rock at 14 m
Photo: eric spenle · CC BY-SA 4.0
The Tremiti are a small limestone archipelago 20 km off the Gargano peninsula, the only islands in the Italian Adriatic and a marine reserve since 1989. The rock is riddled with caves and arches — the Grotta del Bue Marino runs deep enough that divers surface inside it — and the walls carry the yellow cup coral and gorgonians typical of the southern Adriatic. A bronze statue of Padre Pio stands on a submerged rock at 14 m and has become the islands' signature image.
About diving in 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.
Best time to dive Tremiti Islands
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Season | Off-season | Off-season | Fair | Good | Good | Prime | Prime | Prime | Prime | Good | Fair | Off-season |
| Sea surface | 14°C57°F | 13°C55°F | 13°C55°F | 15°C59°F | 18°C64°F | 23°C73°F | 26°C79°F | 27°C81°F | 24°C75°F | 21°C70°F | 18°C64°F | 16°C61°F |
| Daytime high | 16°C61°F | 16°C61°F | 19°C66°F | 22°C72°F | 25°C77°F | 31°C88°F | 33°C91°F | 33°C91°F | 30°C86°F | 26°C79°F | 21°C70°F | 17°C63°F |
| Rain | 62 mm2.4 in | 57 mm2.2 in | 57 mm2.2 in | 41 mm1.6 in | 44 mm1.7 in | 33 mm1.3 in | 37 mm1.5 in | 36 mm1.4 in | 60 mm2.4 in | 91 mm3.6 in | 82 mm3.2 in | 51 mm2.0 in |
| Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|
| Off-season | Off-season | Fair | Good | Good | Prime |
| Sea surface | |||||
| 14°C57°F | 13°C55°F | 13°C55°F | 15°C59°F | 18°C64°F | 23°C73°F |
| Daytime high | |||||
| 16°C61°F | 16°C61°F | 19°C66°F | 22°C72°F | 25°C77°F | 31°C88°F |
| Rain | |||||
| 62 mm2.4 in | 57 mm2.2 in | 57 mm2.2 in | 41 mm1.6 in | 44 mm1.7 in | 33 mm1.3 in |
| Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|
| Prime | Prime | Prime | Good | Fair | Off-season |
| Sea surface | |||||
| 26°C79°F | 27°C81°F | 24°C75°F | 21°C70°F | 18°C64°F | 16°C61°F |
| Daytime high | |||||
| 33°C91°F | 33°C91°F | 30°C86°F | 26°C79°F | 21°C70°F | 17°C63°F |
| Rain | |||||
| 37 mm1.5 in | 36 mm1.4 in | 60 mm2.4 in | 91 mm3.6 in | 82 mm3.2 in | 51 mm2.0 in |
2011–2025 averages. Sea surface: NOAA Coral Reef Watch, measured at the surface, so deeper water can run colder. Daytime high and rain: NASA POWER.
Operators run Apr–Oct with Jun–Sep warmest; winter bora and Adriatic swell close the ferry and the dive centres.
Best months: June, July, August, September
Tremiti Islands water temperature and weather by month
The sea surface runs from 13 °C (55 °F) in February to 27 °C (81 °F) in August. It is 24 °C (75 °F) or warmer from July to September. Most rain falls from September to November, peaking at about 90 mm (3.5 in) in October; June is the driest. Daytime highs reach 33 °C (91 °F) in August and drop to 16 °C (61 °F) in January. The coldest water here is about 13 °C (55 °F), so pack a 7 mm suit with a hood, or a semi-dry.
Dive types & marine life
Grouper hold on the walls, octopus and cuttlefish work the shallow rock, and schools of small reef fish gather around the arches through the June to September peak, with barracuda over the deeper rock. Nudibranchs and other macro reward slow diving in the April, May and October shoulders, and night dives bring the same ground alive again.
- Cave & cavern
- Wall
- Reef
- Night
- Groupers
- Octopus & cuttlefish
- Nudibranchs
- Reef fish swarms
- Barracuda
- Macro critters
Best dive sites in Tremiti Islands
Wreck
Named for the Benedictine cistern above the cove
Cave & cavern
Seventy metres of cave over 2 m of water, with a beach inside
A wooden paddle steamer of 1841, wrecked in an 1864 storm
Wreck
Documented by century and depth alone: 16th century, 25 m
One large black-coral branch grows among the gorgonians
Artificial reef
A saint on the seabed since 1998, 14 m down off Capraia
Wreck
A rock split by three fissures gives the site its name
Punta Diamante
Wall dropping past 40 m with gorgonians and yellow cup coral.
Architiello
Natural rock arch off San Domino, swum through at 12 m.
Grotta delle Viole
Cavern lit through a roof opening, shallow enough for most divers.
How to get to Tremiti Islands
The islands are reached by ferry, year-round from Termoli on the Molise coast and seasonally from the Gargano ports of Vieste, Peschici and Rodi Garganico. San Domino holds the accommodation and the dive centres, and the boats leave from there. Sailings are weather-dependent and thin out in winter.
Photos from Tremiti Islands
Spatuzzi Bruno · CC BY-SA 4.0
Dive videos
Immersioni alle Isole Tremiti - Secca di Punta Secca - Gli Archi · Corsi Sub Roma Diving Line - Scuola d'immersioni on YouTube
Immergersi alle Isole Tremiti - Diving in the Tremiti Islands · Luigi Montevecchi on YouTube
Photo credits
- Turquoise cove ringed by pine-covered slopes in the Tremiti islands, with small boats at anchor by eric spenle, CC BY-SA 4.0, via Wikimedia Commons
- Fortified abbey walls of San Nicola island rising above the sea in the Tremiti archipelago by Spatuzzi Bruno, CC BY-SA 4.0, via Wikimedia Commons
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