Fantasmi Cave in Alghero is a limestone and alabaster cave system featuring a wall and reef environment. The site is reserved for advanced divers due to the overhead environment and potential for low visibility. Depths range from 5 to 30 metres, with an average of 10 metres. Divers should be aware of a thermocline at approximately 12 metres during summer months, where temperatures drop to 13°C. Access is by boat only, and conditions typically feature mild currents. Visibility varies between 10 and 30 metres. Facilities including air fills, equipment rental, and guided tours are available in Alghero.

Stalattiti Cave is a limestone cavern located at Punta del Giglio near Alghero. Formed during the ice age when sea levels were lower, the site features a distinct overhead environment where divers can ascend to a small internal lake to observe stalactites. The dive typically lasts 50 minutes at an average depth of 12 metres, with a maximum depth of 18 metres. Access is by boat only, and the site is suitable for intermediate divers. Conditions include mild currents and water temperatures ranging from 14C to 24C throughout the year. Due to the overhead environment, divers must be aware of entanglement hazards.

Pozzo Cave in Alghero, Italy, offers a diverse underwater experience featuring a cave, reef, and wall topography. Divers typically begin at a shallow pinnacle before navigating along the wall to enter the cave. A notable feature is the exit at a depth of 2 metres, where air bubbles filtering through the limestone create a distinct visual effect. The site reaches a maximum depth of 17 metres with an average of 10 metres. Conditions are generally mild, though the overhead environment requires appropriate caution. Species recorded around this area include wrasses, Mediterranean moray, common octopus, and various nudibranchs. Boat access is required for this site, which is suitable for beginners.

Bramassa is a diverse marine site located in Alghero, Italy, offering a variety of underwater topography including reefs, walls, caves, and canyons. The site is accessible by boat and is suitable for beginners, with depths ranging from 8 to 15 metres and an average depth of 12 metres. Divers can explore tunnels and windows that create distinct light effects, particularly during the afternoon. Conditions are generally mild, though divers should remain aware of boat traffic in the area. The site provides a varied environment for those interested in geological formations and coastal Mediterranean diving.

Falco Cave is a cavern and reef site located 4000 metres off the coast of Alghero. The site features a wide entrance and exit, leading to an internal lake where divers can surface to explore a dry cave area containing stalactites. The dive typically lasts 70 minutes at an average depth of 10 metres, with a total depth range of 6 to 18 metres. Conditions include mild currents and visibility ranging from 10 to 25 metres. Access is by boat only. Hazards include an overhead environment, potential for low visibility, and entanglement risks. The site is suitable for beginners and supports night diving.

Spiaggia del Lazzaretto features a sandy main beach flanked by ten small rocky coves to the north. These shallow inlets provide accessible conditions for snorkelling, making the site suitable for beginners. Water temperatures fluctuate between 14C and 26C throughout the year, with cooler conditions common outside of the summer months. Currents are generally mild. Species recorded around this area include wrasses, which are very common during July and August, alongside less frequently encountered marine life such as Mediterranean Moray, Common Octopus, Great Barracuda, and various nudibranchs. On-site facilities include parking, showers, changing rooms, a rinse station, equipment rental, and a cafe.

Cala Bramassa is a reef and cave site located within the Porto Conte Regional Park near Alghero. Situated 1500 metres from the shore, this site features a rocky seabed with depths ranging from 2 to 18 metres, averaging 12 metres. The bay's shape provides protection from most winds, resulting in visibility between 5 and 20 metres. Water temperatures fluctuate between 14C and 26C, with the bay being slightly warmer than neighbouring coves. Access is possible by both shore and boat, though the site is best suited for intermediate snorkellers. Hazards include entanglement, overhead environments within the caves, and sharp coral. Parking is available for visitors.

Capo Galera is a rocky headland near Alghero featuring a series of underwater arches and small caves. The site is suitable for intermediate divers, with depths ranging from 5 to 15 metres and an average depth of 10 metres. Divers and snorkellers can expect visibility between 15 and 30 metres. Water temperatures fluctuate seasonally from 14C to 25C, with a thermocline typically occurring at 12 metres where temperatures drop to 15C. Access is available via both shore and boat. Facilities at the location include parking, toilets, showers, changing rooms, a rinse station, air fills, equipment rental, a cafe, a dive shop, boat charter, guided tours, and gear storage.