Glaronisi Rock is a small rocky islet located 60 metres from the shore near Otzias beach in Attica, Greece. This reef site features a rocky terrain with depths ranging from 15 to 30 metres, averaging 25 metres. Access is by boat only. The site is suitable for intermediate divers due to the presence of moderate currents. Snorkellers can also enjoy the area, which holds a rating of 4 out of 5. Divers should be aware of potential hazards, including lionfish and strong currents. Local facilities provide air fills, equipment rental, and guided tours to support diving activities.

Spathi Beach on Kea Island offers a rocky reef environment suitable for intermediate snorkellers. The eastern coastline features a rugged rocky shelf that extends into the water. Access is via the shore, and the site is equipped with parking, toilets, showers, changing rooms, and a cafe. Water temperatures range from 16C in winter to 26C in August. Divers and snorkellers should be aware of sharp coral in the area. Conditions generally feature mild currents, though these can vary. A dive shop is available on-site to support water activities.

Kefalas Beach, located on the north coast of Kea Island in Attica, Greece, is a reef site primarily accessed by boat. This location is suitable for beginners, offering a snorkel rating of 3 out of 5. The site features sandy shallows where the topography is defined by the seabed. Conditions are generally mild, with water temperatures ranging from 16C in the winter months to 26C in August. Divers and snorkellers should be prepared for mild currents while exploring the area.

Kalidonixi Cove in Attica, Greece, is a sheltered marine site featuring a combination of reef structures and seagrass meadows. Accessible only by boat, the cove offers a shallow environment suitable for beginners, with depths ranging from 1 to 10 metres and an average depth of 5 metres. Snorkellers can expect mild currents and visibility typically between 10 and 20 metres. Water temperatures fluctuate throughout the year, ranging from 16C in the winter months to a peak of 26C in August. The site provides a calm setting for observing the underwater topography of the seagrass beds and reef formations.

Marades is a wreck dive site in Attica, Greece, featuring the remains of a small cargo ship approximately 30 metres in length. Resting at a consistent depth of 10 metres, this site is suitable for beginners and serves as an accessible dive. Access is by boat only. Divers should be aware of potential entanglement hazards within the wreck structure. Visibility at the site ranges from 5 to 20 metres, with mild currents typically present. Water temperatures fluctuate throughout the year, ranging from 16C in the winter months to 26C in August. A typical dive at this location lasts around 40 minutes.

The HMHS Britannic is a significant technical dive site located off Kea Island, Attica. Resting at depths between 110 and 122 metres, the wreck of this sister ship to the Titanic remains largely intact, with recognisable features including the hull, funnels, davits, and superstructure. This site is reserved for expert divers due to the extreme depth, substantial decompression requirements, and strong currents. Visibility varies between 10 and 30 metres. Access is strictly by boat, and divers must manage hazards including overhead environments, nitrogen narcosis, and active boat traffic. Meticulous dive planning and redundant gas supplies are essential for all visitors to this deep-water wreck.

Ksyla Bay, located off Kea Island in Attica, features a combined reef and wall topography. The site reaches depths between 20 and 30 metres, with an average depth of 22 metres. Visibility is consistently 30 metres, providing clear sightlines along the wall face and reef structure. This site is suitable for advanced divers due to the depth. Access is by boat only, and guided tours are available through local dive shops. Divers should monitor their depth gauge and gas supply closely, as the wall reaches 30 metres. The site operates year-round with no notable current, allowing for controlled exploration of the two distinct environments.

Xyla Beach in Attica, Greece, features a secluded cove located south of the main beach. This reef site offers varied underwater topography with depths ranging from 2 to 30 metres, averaging 22 metres. Access is via a shore entry, and the site is suitable for intermediate snorkelers and divers. Conditions are variable, with visibility ranging from 5 to 30 metres and mild currents. Divers should be aware of potential surf conditions at this location. Parking is available for visitors. A typical dive session lasts approximately 60 minutes.