Ardglass Gullies in Strangford Lough features a series of underwater gullies carved into folded sedimentary rock. The site includes a small sea cave, creating a complex topography for snorkellers. The walls of the gullies are covered in kelp, sponges, and anemones. Water temperatures at this site range from 9C to 15C throughout the year. Due to the presence of an overhead environment, surf, and cold water, this site is recommended for intermediate snorkellers. Entry is via the shore. Snorkellers should be prepared for variable conditions typical of this marine environment.

Sheepland is a rocky reef site located in Strangford Lough near Ardglass. This shore-entry dive offers depths ranging from 1 to 20 metres, with an average depth of 5 metres. Divers can expect mild currents and visibility between 5 and 15 metres. The water temperature remains cold throughout the year, typically between 9C and 15C, necessitating the use of a thick 5/4mm wetsuit with boots and a hood. The site is suitable for intermediate divers and provides a 4/5 rating for snorkelling. Hazards include jellyfish, sea urchins, and sharp coral. Parking is available at the site.

St. Patrick's Well at Ardtole offers a rugged shore entry into the marine environment of Strangford Lough. The site is characterised by a rocky seabed featuring extensive kelp forests and deep rock pools that are accessible at low tide. Divers should be prepared for cool water temperatures ranging from 9C to 15C throughout the year, necessitating appropriate thermal protection for extended exposure. This site is suited for intermediate divers due to the presence of strong currents and surf conditions. Snorkelling is also possible at this location, though conditions vary based on the local sea state.

The Water Rock in Strangford Lough is a shallow reef and artificial reef site suitable for beginners. Access is via a shore entry at the slipway of the historic stone pier. The site is shallow, with depths ranging from 0 to 5 metres and an average of 2 metres. It is best explored at high tide, as the harbour dries out significantly at low water. Conditions include mild currents and visibility between 3 and 10 metres. Species recorded around this area include gray seals, curled octopus, wrasses, catsharks, squat lobsters, common lobsters, sea slugs, gurnards, orange-clubbed nudibranchs, giant jellyfish, flatworms, conger eels, crabs, and sea stars. Hazards include entanglement and low visibility.

Killough Harbour near Coney Island is a sheltered marine site located within Strangford Lough. The topography features a combination of sandy areas and rocky ledges surrounding the island, providing a protected environment for snorkellers. Water temperatures in this region fluctuate between 9C and 15C throughout the year. Access to the water is via the shore, making this a suitable location for beginners. The site is rated 3/5 for snorkelling, offering a calm setting for exploring the local underwater terrain.

Water Rock is a prominent rocky outcrop located at the entrance to Killough Bay in Strangford Lough. This site features underwater reefs characterised by mixed algae and dense kelp forests. Divers and snorkellers can explore depths ranging from 2 to 18 metres. Access is by boat, as the site is situated 400 metres from the shore. Conditions include moderate currents and water temperatures between 9C and 15C. Species recorded around this area include grey seals, curled octopus, wrasses, conger eels, catsharks, and various crustaceans such as common lobsters and squat lobsters. Due to boat traffic, divers should exercise caution during their 45-minute dives.

Gun's Island in Strangford Lough features a topography of sheer underwater walls and rocky gullies. Located 183 metres offshore, the site requires boat access and is suited for advanced divers due to moderate to strong currents. Depths reach up to 16 metres over a rocky seabed. Water temperatures range from 9C to 15C throughout the year. Species recorded around this area include Gray Seal, Curled Octopus, Common Lobster, Conger Eel, Catshark, and various nudibranchs and sea stars. The site is also suitable for snorkelling.

Rossglass Beach in Strangford Lough offers a relaxed shore-entry snorkelling experience suitable for beginners. The site features an expansive beach with numerous rock pools and shallow channels that become exposed at low tide. Divers and snorkellers can explore depths ranging from 1 to 5 metres, with an average depth of 3 metres. Conditions are generally mild, though visibility varies between 3 and 10 metres. Water temperatures remain cool, fluctuating between 9C and 15C throughout the year. Species recorded around this area include various crabs, sea stars, brittle stars, and occasionally larger marine life such as seals or octopuses. Be aware of jellyfish, which are a known hazard in these waters.