Isola di Nisida features a diverse underwater topography comprising a reef, wall, and drop-off. Divers can explore depths ranging from 12 to 32 metres, with an average depth of 15 metres. The site is accessible from the shore, though caution is required during entry due to surf and a shore break. Visibility is excellent at 30 metres. While no currents are present, the significant depth requires careful monitoring of dive profiles. Species recorded around this area include wrasses, bream, Mediterranean moray, common octopus, and European common cuttlefish. Facilities on site include showers and changing rooms. Night diving is permitted at this location.

Portus Julius is a submerged archaeological site located in Baia, featuring the remains of a port commissioned in 37 BC by Marco Vipsanio Agrippa. Divers can explore the ancient port structures and preserved mosaics at depths ranging from 3m to 5m, with an average depth of 4m. The site is situated 500m from the shore and requires boat access. Conditions are generally mild with visibility between 3m and 15m. The site is suitable for beginners, with typical dives lasting 45 minutes. Facilities available include changing rooms, showers, and guided tours. Divers should be aware of potential entanglement hazards due to the nature of the submerged ruins.

Secca delle Fumose is a unique dive site located 800 metres off the Sorrento Peninsula. This artificial reef consists of several submerged pylons, believed to be remnants of the ancient Portus Julius. The site is defined by its volcanic activity, where active fumaroles and geysers release gas bubbles and hot water from the seabed, creating localized thermal anomalies and sulfur deposits. Divers can explore these colonized pillars at depths ranging from 9 to 16 metres, with an average depth of 12 metres. The site is accessible by boat and features mild currents. Facilities including changing rooms, showers, and guided tours are available for visitors.

Secca di Miseno is a boat-access site on the Sorrento Peninsula featuring a combination of natural reef, wall, and artificial reef structures. The terrain spans depths from 22 to 45 metres, with an average depth of 30 metres. Visibility typically ranges between 10 and 30 metres, and water temperatures fluctuate from 14C to 18C. Due to the significant depth, the site presents risks including decompression requirements and nitrogen narcosis. Divers should monitor depth and nitrogen saturation levels closely. The site is suitable for intermediate divers and supports night diving. Facilities including air fills, changing rooms, showers, and guided tours are available nearby.

Parco Sommerso di Baia is a submerged archaeological site featuring Roman ruins, including mosaic floors and columns, resting at depths between 3 and 13 metres. These structures were submerged due to volcanic subsidence. The site offers visibility ranging from 15 to 20 metres with mild currents, making it suitable for both divers and snorkellers. Entry is possible from the shore or by boat. In the Secca Fumosa area, sulphurous fumes create localized hot water pockets. Divers should remain aware of boat traffic and potential entanglement risks when navigating the overhead environments of the ruins. Facilities on shore include parking, toilets, showers, and rinse stations.

Ninfeo di Claudio is an underwater archaeological site featuring a rectangular building and a reconstruction of a dynastic portrait gallery of the Julio-Claudian dynasty. Located 400 metres from the shore, the site is accessed by boat and sits at a shallow depth of 3 to 5 metres, with an average of 4 metres. Divers can explore the structure and the nearby paved Via Herculanea. Conditions are generally mild with visibility ranging from 15 to 20 metres. The site is suitable for beginners, with typical dives lasting 45 minutes. Facilities including changing rooms, showers, air fills, and guided tours are available. Divers should be aware of the potential hazard of entanglement.

Terme del Lacus is a marine dive site located within Zone A of the park in Ischia, Italy. This site is notable for a submerged polychrome mosaic discovered on the seabed. The site is shallow, with an average depth of 4 metres and a maximum depth of 5 metres. Access is strictly by boat. Conditions include mild currents and visibility ranging from 3 to 10 metres. Water temperatures fluctuate between 14C in March and 27C in August. Divers should be aware of potential hazards including entanglement and sharp coral. Facilities available at the site include air fills, equipment rental, changing rooms, showers, and a rinse station.

Villa con Ingresso a Protiro is a submerged archaeological site located within the Baia archaeological park off the coast of Ischia. This monumental complex features the remains of an ancient urban structure, including a street, taverns, and a private villa defined by its small portico. Divers can explore a series of rooms surrounding a central atrium, where black and white mosaic tiles remain visible on the floor. The site is shallow, with an average depth of 4 metres, and is accessible only by boat. Conditions are generally mild, though divers should remain aware of boat traffic in the area. The site is suitable for beginners.