Ay Yani offers a combination of reef and wreck diving located in the Marmara Sea. The site sits at depths between 39 and 45 metres, requiring advanced buoyancy control and careful management of bottom time. Divers access the site by boat, encountering mild currents and visibility ranging from 5 to 10 metres. Water temperatures fluctuate between 10 and 19 degrees Celsius throughout the year, with a thermocline present. Due to the depth and low visibility, this site is suited for intermediate divers. Divers should exercise caution regarding the depth and potential for sharks in the area.

Kara ev Sedef is a reef site located in the Princes' Islands, Turkey, within the Marmara Sea. The site is suited for intermediate divers, offering depths between 30 and 40 metres. Divers can access the reef from either the shore or by boat. Conditions are characterised by mild currents and visibility ranging from 10 to 20 metres. Water temperatures fluctuate significantly throughout the year, ranging from 10 to 19 degrees Celsius. Due to these cold temperatures, adequate thermal protection, such as a 7mm wetsuit or a drysuit, is necessary. Divers should monitor their depth and navigation closely as visibility can vary during the dive.

Büyükada Kurşun Burnu is a reef and drift dive site located in the Princes' Islands, Turkey. This site is suited for advanced divers due to strong currents and depths ranging from 8 to 30 metres, with an average depth of 25 metres. Access is strictly by boat, and divers must remain vigilant regarding boat traffic in the area. The underwater environment supports a variety of regional marine life and invertebrates typical of the Marmara Sea habitat. Dives typically last 45 minutes, with water temperatures fluctuating between 10C and 19C throughout the year. The site is noted for its challenging conditions and suitability for deep diving.

Pigeon Cave in the Princes' Islands is a shallow, sheltered cave dive located in the Marmara Sea. With a consistent depth of 3 metres and no current, it serves as a suitable location for beginner divers gaining experience in overhead environments. Visibility typically ranges from 5 to 10 metres. Access is by boat, which allows for direct arrival at the cave entrance. The water temperature varies significantly throughout the year, ranging from 10C to 25C. Divers should exercise caution regarding buoyancy and wear gloves, as the cave features sharp rock edges on the walls and floor. Be mindful of surge and swell conditions during boat entry and exit.

Prince Islands in the Marmara Sea offers boat-based diving at depths ranging from 5 to 30 metres. Divers should be prepared for strong currents and variable visibility between 10 and 20 metres. A distinct thermocline is often encountered around 10 metres, where warmer surface layers meet colder water below. Visibility typically improves at depths of 20 metres. Due to the strong currents and depth, this site is suited for intermediate divers. Boat traffic is a notable hazard in the area, requiring careful surface management. Water temperatures fluctuate throughout the year, ranging from 10C in the winter months to 19C in October.

The Karakaya Wreck is a marine dive site located off Heybeliada in the Princes' Islands. Resting at depths between 20 and 30 metres, the wreck provides a technical challenge for intermediate divers interested in penetration and navigation. Visibility at the site is variable, ranging from 3 to 20 metres, while currents remain mild. Water temperatures fluctuate between 10 and 19 degrees Celsius throughout the year, necessitating appropriate thermal protection. Access is strictly by boat. Divers should be aware of hazards including boat traffic and potential entanglement within the wreck structure. The site supports a variety of regional marine life and invertebrates typical of the Marmara Sea habitat.

Neandros Kufos reef is a deep-water site located in the Marmara Sea, requiring advanced certification and precise buoyancy control. The reef structure sits at depths between 25 and 35 metres, with an average depth of 25 metres. Divers must navigate moderate currents and visibility ranging from 5 to 10 metres. Due to water temperatures fluctuating between 10 and 19 degrees Celsius, full exposure protection is essential. Access to this site is by boat only, located over 2,400 metres from the shore. Divers should exercise caution regarding cold water and the presence of stonefish, avoiding contact with the seabed or reef structure at all times.

Pendik Sualtı Sporları Kulübü, located in the Princes' Islands, offers a combination of natural and artificial reef structures. This shore-entry site is suitable for beginners and training, with water temperatures ranging from 10C in winter to 25C in summer. Divers should be aware of variable visibility and moderate currents, which can shift daily. The site features an overhead cave environment, requiring careful monitoring of depth and air supply. Hazards include potential encounters with stonefish and sea urchins, as well as sharp coral. The local dive shop provides air fills, equipment rental, and guided tours to assist with site access and safety.