Bengore Head is a boat-access site situated between Dunseverick and the Giant's Causeway. The topography is defined by massive underwater boulders and vertical walls that descend into deep water. Due to the challenging nature of the terrain and the depth, this site is suited for advanced snorkellers. Water temperatures at this location fluctuate between 8C and 14C throughout the year. The site offers a rugged underwater landscape shaped by its geological features, providing a distinct environment for exploration in the waters of Northern Ireland.

Port Moon in Strangford Lough features dramatic underwater topography defined by basalt columns, caves, and a drop-off. This former salmon fishery offers a varied environment including reef structures and kelp forests. The site is suitable for advanced divers due to moderate currents and cold water temperatures ranging from 8C to 14C. Entry is possible via both shore and boat, with a steep cliff path providing access for shore entries. Snorkellers can also enjoy the site, which is rated 5/5 for the activity. Divers should be aware of potential hazards including cold water, sharp coral, and surf conditions. Facilities at the location include parking and toilets.

Dunseverick Cove, also known as Castle Beach, is a small sandy site situated beneath the ruins of Dunseverick Castle in Strangford Lough. The topography consists of shallow rocky reefs flanking the beach, interspersed with seagrass beds. This site is suitable for beginners, with depths ranging from 0 to 10 metres and an average depth of 5 metres. Divers and snorkellers should be aware of mild currents, potential surf, and cold water temperatures between 8C and 14C. Species recorded around this area include seals, catsharks, various crustaceans, and jellyfish. Access is via the shore, with parking available nearby. Typical dives last approximately 30 minutes.

Portbraddon Slipway provides shore access to a marine environment featuring a mix of reef and artificial reef structures. Located at the western end of White Park Bay, the site transitions from a rocky shoreline into a sandy seabed. Divers and snorkellers can explore depths ranging from 4 to 10 metres. Conditions at this site are variable, with moderate currents, surf, and potential rip currents present. The site is suitable for beginners, though caution is advised regarding water conditions. Facilities including parking and toilets are available near the slipway.

The Slough is a deep natural inlet in Strangford Lough, characterised by basalt rock ledges that provide access to deep water. This site functions as a sheltered swimming pool, making it suitable for intermediate divers and snorkellers. Entry is via the shore, though users should be aware of potential hazards including cold water, surf, and rip currents. Water temperatures range from 8C to 14C throughout the year, necessitating appropriate thermal protection. Species recorded around this area include harbour and grey seals, various jellyfish, common lobsters, crabs, sea hares, sea stars, and snails. Facilities at the site include parking, toilets, and showers.

Dunseverick Harbour in Strangford Lough offers a sheltered shore entry point for snorkelers. The site features deep pools and gullies, with the seabed dropping sharply beyond the harbour wall into a field of cobbles and boulders. Water temperatures at this location range from 8C in March to 14C between August and October. Species recorded around this area include harbor and gray seals, various crab species, sea stars, brittle stars, and jellyfish. Snorkelers should be aware that conditions vary at this site, which is rated 3 out of 5 for snorkeling activities.

Mermaid's Cave is a sea cave situated directly beneath the ruins of Dunluce Castle. The site features a cavern reaching 60 feet in height and an adjacent limestone reef. Snorkellers can access the site from either the shore or by boat. Water temperatures at this location vary between 8C and 15C throughout the year. Due to the nature of the cave environment and local conditions, this site is best suited for intermediate snorkellers. The area is rated 4 out of 5 for snorkelling activities.

Portbraddan, located at the western end of White Park Bay, provides shore access to rocky outcrops and kelp-covered reefs. This site is suitable for intermediate divers and snorkellers, with depths starting at 4 metres. The area is generally sheltered compared to nearby open beaches, though surf can be a hazard. Water temperatures range from 8C to 14C throughout the year. Parking is available for visitors. The site is well-suited for exploratory snorkelling along the shoreline, where the rocky topography supports a kelp forest environment.