Cala Sinzias features a diverse underwater topography, transitioning from a shallow 5-metre reef to a wall that descends to 40 metres. An artificial reef provides additional structure to the site. Divers should be prepared for a shore entry that involves navigating a surf and shore break, requiring careful timing during a lull. Once submerged, moderate currents are common and can fluctuate, necessitating careful dive planning. Visibility can reach up to 50 metres, though conditions vary. Given the water temperatures ranging between 15 and 19 degrees Celsius, a suitable wetsuit is recommended for all dives at this location.

Punta Molentis in Villasimius is a shallow reef site suitable for beginners and snorkellers. Located 200 metres from the shore, the site features an average depth of 3 metres, with a range between 1 and 5 metres. Divers and snorkellers can expect mild currents and visibility ranging from 10 to 25 metres. Entry is via the shore, making it an accessible location for those seeking calm, shallow waters. The area is monitored, though visitors should remain aware of boat traffic in the vicinity. Facilities including equipment rental, air fills, and rinse stations are available nearby to support diving and snorkelling activities.

Secca di Santa Caterina is a complex site featuring a reef, pinnacle, and cave system located 2000 metres off the coast of Villasimius. The site is suitable for intermediate divers, with depths ranging from 12 to 38 metres and an average depth of 15 metres. Access is by boat only. Divers encounter mild currents and visibility typically between 15 and 30 metres. Water temperatures fluctuate between 15C and 19C throughout the year. Species recorded around this area include European common cuttlefish, Mediterranean moray, common octopus, Turkish wrasse, European parrotfish, various bream species, painted comber, tompot blenny, and castagnole. Hazards include sharp coral and the potential for strong currents.

I Tubi is a reef and wall site located 800 metres off the coast of Villasimius, Italy. The site features an artificial reef structure and offers a depth range between 7 and 40 metres, with an average depth of 12 metres. Access is strictly by boat. Divers should be aware of moderate to strong currents, and visibility typically ranges from 10 to 40 metres. Water temperatures fluctuate between 15C and 19C, with thermoclines often occurring around 12 metres where temperatures may drop to 15C. The site is suitable for beginners and supports night diving, with typical dive durations of 45 minutes.

Nave Romana in Villasimius is a combined wreck and reef site located 1000 metres from the shore. The site features a depth range of 5 to 38 metres, with an average depth of 15 metres. Access is strictly by boat, and the site is suited for intermediate divers due to the presence of moderate currents and significant depth. Visibility typically ranges between 15 and 30 metres. Water temperatures fluctuate between 15C and 19C throughout the year. Divers should be aware of the deep water and potential for strong currents during their 40-minute dives. Local facilities include air fills, dive shops, and guided tours.

Madonna del Naufrago is a monumental sculpture submerged in 1979 near Isola dei Cavoli, Villasimius. Located at an average depth of 11 metres, the site features an artificial reef structure surrounded by rocky areas. It is accessible only by boat, situated 8 kilometres from the shore. Divers and snorkellers can expect mild currents and visibility ranging from 5 to 25 metres. The site is suitable for beginners, with water temperatures fluctuating between 15C and 26C throughout the year. Species recorded around this area include common octopus, Turkish wrasse, European parrotfish, grey triggerfish, striped red mullet, various bream species, painted comber, tompot blenny, castagnole, crabs, and Mediterranean cardinalfish.

I Grottini in Villasimius, Italy, is a marine cave and reef site suitable for intermediate divers. The site features a depth range of 13 to 14 metres, with an average depth of 14 metres. Access is strictly by boat. Divers can expect mild currents and visibility ranging from 15 to 30 metres. Typical dive times are approximately 45 minutes. Due to the nature of the cave environment, divers should be aware of potential hazards including entanglement and sharp rock formations. Water temperatures fluctuate throughout the year, ranging from 15C in the winter months to 25C during the peak of summer.

Santa Caterina is a pinnacle and reef site located 1500 metres offshore in the Capo Carbonara Marine Protected Area near Villasimius. The site features a varied topography starting at 15 metres and descending to 40 metres, with an average depth of 25 metres. Access is strictly by boat. Divers should be prepared for mild to strong currents, which require intermediate skill levels. Visibility at the site ranges from 10 to 30 metres. Water temperatures remain between 15C and 18C throughout the year. Typical dives last approximately 45 minutes. Facilities including air fills, equipment rental, and boat charters are available locally.