Grotta dei Cervi

The dive

Grotta dei Cervi is one of fifteen submerged caves the Capo Caccia - Isola Piana marine protected area lists by name and by coordinate, and the AMP puts it at Punta Giglio, 40 34.092 N 8 12.311 E, on the seaward flank of the promontory that closes the Gulf of Porto Conte. Italian Wikipedia describes it as a three-level cave: an outer air level, an inner air level and an inner submerged one. The outer submerged part runs at roughly 15 to 20 m; Capo Galera Diving, which works the site, puts the entry to the siphon at about 10 m and describes it as small. Through the siphon the cave opens into a chamber with air in the roof.

What is in that chamber is the reason to dive it. Set into calcite concretions and stalactites in a semi-emergent niche above the inner lake are the remains of Megaloceros cazioti algarensis, the dwarf Sardinian deer descended from the giant deer of the mainland and extinct for tens of thousands of years. Italian Wikipedia records numerous bones and complete skulls with the antlers still attached, carbon-dated to roughly 120,000 to 75,000 years ago, and attributes the deposit to animals that sheltered in the cave when the sea was much lower and fell through an internal opening into the chamber below. The cave was found in September 1995 during exploratory diving, a year after the same explorers found the Grotta dei Fantasmi 240 m away.

This is an overhead environment inside a marine protected area, and both halves of that sentence carry rules. The AMP's 2026 implementing regulation bars diving and freediving outright in zone A. In zones B and C, diving requires authorisation from the managing body, daylight only, no solo diving, and a certificate of at least second level. For the listed submerged caves a diver going in without a guide must hold at least a first-level cave specialty, Cavern Diver or equivalent; on a guided visit the guide must hold that specialty and each diver a second-level certificate. The table caps Grotta dei Cervi specifically at six divers per dive and three dives per day, boats moor only on the AMP's own marked buoys, and no underwater activity may be run at night. Teaching inside a cave is permitted in one cave only in the whole AMP, and it is not this one: it is the Grotta del Pozzo, 770 m to the north-west.

The life here is cave and semi-dark rock fauna rather than open reef. Occurrence records at this pin are dominated by sponges and shade-loving invertebrates: Petrosia ficiformis, Agelas oroides, Spongia lamella, the red sea squirt Halocynthia papillosa, the Mediterranean banded coral shrimp Stenopus spinosus, the monk shrimp Lysmata seticaudata, the common prawn Palaemon serratus, the sponge crab Dromia personata, the dotted sea slug and Felimare tricolor. Leopard-spotted goby, cardinalfish, conger, brown wrasse, black-faced blenny and common octopus are all on the list, and Capo Galera reports barracuda, schools of seabream and large grouper on the wall outside the entrance.

• Bones, skulls and antlers of the extinct dwarf Sardinian deer set in calcite above the inner lake
• A three-level cave with an air chamber reached through a siphon
• Listed by the AMP with its own coordinate and a cap of six divers per dive
• Sponge and shade fauna on the wall outside: Petrosia ficiformis, Agelas oroides, banded coral shrimp, leopard-spotted goby

Conditions

The cave lies on the seaward side of Punta Giglio, so the day is decided by the swell on that flank rather than by the cave, which is still inside. When Capo Caccia's exposed points are unworkable the centres move round into the Gulf of Porto Conte instead.

On current: No source publishes a current figure for this cave. The two depth statements differ in what they measure: Capo Galera gives about 10 m for the siphon entrance, Italian Wikipedia gives roughly 15 to 20 m for the outer submerged part of the cave, and the air chamber sits above the water inside. The 10 to 20 m band carried here spans both.