Blackhead Caves, located at the southern base of Islandmagee, offer a shallow dive experience consisting of rocky reefs and sea caves. The site is suitable for intermediate divers, with depths ranging from 1 to 10 metres and an average depth of 5 metres. Access is via a shore entry. Divers should be prepared for moderate currents and surge, as well as potential hazards including entanglement, low visibility, and the overhead environment of the caves. Visibility at the site varies between 5 and 20 metres. Water temperatures fluctuate between 8C and 14C throughout the year. Parking is available for visitors.

The Gobbins is a marine site situated at the base of dramatic basalt cliffs in Strangford Lough. This location features a combination of caves and drop-offs, providing a unique perspective of the cliff-base topography. Access is strictly by boat, and the site is suited for advanced snorkelers due to the presence of moderate currents, surge, and surf. Water temperatures range from 8C to 14C throughout the year. Divers and snorkelers should remain vigilant regarding boat traffic, cold water conditions, and the presence of jellyfish. Facilities including parking, toilets, a cafe, and equipment rental are available nearby.

Fisherman's Quay in the Scotch Quarter of Carrickfergus offers a shore-entry snorkel site situated in the shadow of Carrickfergus Castle. The site features a rocky seabed and is classified as an artificial reef. Depths range from 1m to 5m, with an average of 3m. Conditions include moderate currents and visibility ranging between 3m and 10m. Water temperatures are consistently cold, fluctuating between 8C and 14C throughout the year. Due to the environment, snorkelers should be aware of boat traffic, cold water, and low visibility. Facilities available at the location include parking, a cafe, and showers.

Smelt Mill Bay is a pebble beach cove located at the base of Strickland's Glen in Strangford Lough. This site features rock formations and gullies suitable for snorkeling. The area is accessible via shore entry and is generally suited for beginners. Depths range from 1 metre to 10 metres, with an average depth of 5 metres. Conditions include mild currents and water temperatures varying between 8C and 15C throughout the year. Divers and snorkellers should remain aware of potential boat traffic and surf conditions in the area. Parking is available for visitors.

Jenny Watts Cove in Strangford Lough is a sheltered reef site suitable for beginners. Divers and snorkellers access the water via a slipway or a set of steps with a handrail that leads into a rocky gully. Conditions are generally mild, though visitors should be aware of surge, boat traffic, and cold water temperatures ranging from 8C to 15C. Marine life recorded at the site includes very common sea squirts and snails. Divers may also encounter uncommon sea slugs, barnacle-eating dorids, crabs, common sea stars, grey sea slugs, rock crabs, and European green crabs. Rare sightings include wrasses, tompot blennies, sea stars, and brittle stars. Facilities include parking, toilets, showers, and changing rooms.

Swineley Bay in Strangford Lough offers a shore-entry snorkelling experience featuring a combination of reef and kelp forest habitats. The site is accessed via a coastal path and provides facilities including parking, toilets, showers, changing rooms, and a cafe. Water temperatures at this location vary between 8C and 15C throughout the year. Due to the nature of the terrain and the environment, this site is best suited for intermediate-level snorkellers. The bay is noted for its peaceful conditions and is rated 4/5 for snorkelling activities.

Isle of Muck (South Point) in Strangford Lough offers a challenging snorkel experience characterised by a dramatic boulder slope and vertical walls. The site is suitable for advanced snorkellers due to the nature of the terrain and variable conditions. Access is possible via both shore and boat entries. Water temperatures at this location range from 8C in March to 14C during the late summer months of August, September, and October. The underwater topography provides a rugged environment for exploration, though snorkellers should be prepared for the temperate conditions typical of this region.

Grey Point Fort in Strangford Lough offers a rugged snorkeling experience characterised by deep gullies and large boulders along the rocky shoreline. The site provides access to deeper water close to the shore, suitable for intermediate snorkelers. Conditions vary, with water temperatures ranging from 8C to 15C throughout the year. Snorkelers should be aware of potential hazards including boat traffic, jellyfish, surf, and periods of low visibility. Species recorded around this area include catsharks, wrasses, various crabs, lobsters, and sea stars. Parking is available at the site, and guided tours can be arranged for those exploring the area.