Thumb Rock is a reef site located 900 metres off the coast of Mullaghmore, Ireland. The reef structure extends to a maximum depth of 25 metres, with the most notable topography found in the shallower sections averaging 15 metres. Divers can expect visibility between 4 and 10 metres. Due to the potential for strong currents and surf, boat access is required. Water temperatures range from 9C to 16C, necessitating the use of a drysuit or thick wetsuit. While the site is suitable for beginners, divers should monitor conditions closely as swells can develop rapidly on this stretch of the Atlantic coast.

Thumb Rock is an offshore limestone reef located 370 metres from the shore at Mullaghmore. The site features vertical walls that descend to depths between 10 and 25 metres. Due to the presence of strong currents and surf, this location is suitable for advanced divers only. Access is by boat, and the site is marked by a buoy. Water temperatures are cold, ranging from 9C to 16C, necessitating the use of thick wetsuits. Visibility at the site typically varies between 4 and 10 metres. The reef structure provides a distinct underwater topography for those exploring the area.

Bishop's Pool is a natural tidal pool carved into the limestone shelf of Mullaghmore Head. This sheltered, enclosed environment provides a site for diving and snorkelling even when Atlantic swells are active nearby. The site is suitable for beginners, with depths ranging from 1 to 5 metres and an average depth of 3 metres. Entry is via the shore. Conditions vary, with mild currents, potential surf, and hazards including entanglement and jellyfish. Species recorded around this area include harbour seals, common lobsters, sea stars, and various jellyfish species. Water temperatures range from 9C to 16C, with the pool occasionally retaining heat from the sun to become warmer than the surrounding ocean.

Streedagh Point in Mullaghmore offers a unique snorkelling experience across limestone ledges and fossil beds dating back 350 million years. This site features a mix of reef and wreck topography with depths ranging from 3 to 20 metres, averaging 5 metres. Access is via the shore at the northern end of Streedagh Strand. Conditions are variable, with visibility between 2 and 10 metres and water temperatures fluctuating from 9C to 16C throughout the year. Due to strong currents, rip currents, and surf, this site is suited for intermediate snorkellers. Facilities including parking and toilets are available nearby.

Skuddagh Rock, located off Mullaghmore, Ireland, offers a combination of open reef and cave diving. The site features depths ranging from 20 to 30 metres, with an average of 25 metres, though it can reach 33 metres. Divers experience moderate currents and visibility between 10 and 30 metres. The presence of caves and swim-throughs creates an overhead environment, requiring appropriate training and buoyancy control. Access is by boat only, and a drysuit is recommended due to water temperatures ranging from 9 to 15 degrees Celsius. Species recorded around this area include harbour seals, wrasses, nudibranchs, sea stars, soft corals, and various crustaceans.

St. John's Point in Mullaghmore offers a shore-accessible dive featuring a steep underwater wall and a vibrant kelp forest. Divers enter via concrete steps located near the lighthouse. The site reaches depths between 8 and 30 metres, with an average depth of 15 metres. Conditions vary, with visibility ranging from 5 to 20 metres and mild currents. The site is suited for intermediate divers and provides a 5/5 rating for snorkelling. Species recorded around this area include harbour seals, compass jellyfish, orange-clubbed nudibranchs, wrasses, sea stars, soft corals, snails, dead man's fingers, European green crabs, and sea cucumbers. Parking is available at the site.

Coral Beach in Mullaghmore is a distinctive site defined by its unique maerl composition, a calcified seaweed that provides the sand with a pinkish hue. The site features a varied topography including reefs, walls, and caves. Divers and snorkellers can access the water directly from the shore, with the site located 50 metres out. Depths range from 1 to 30 metres, with an average of 10 metres. Conditions vary, with visibility between 5 and 25 metres and mild currents. Hazards include boat traffic, surf, surge, and cold water temperatures ranging from 9 to 15 degrees Celsius. Parking is available for visitors.

Clashymore is a remote snorkelling site located within a natural rocky gut on the southern side of the uninhabited Inishmurray Island. Accessible only by boat, this site is suited for advanced snorkellers due to its exposed location. The environment consists of a rocky topography typical of the Atlantic coastline. Water temperatures at the site fluctuate throughout the year, ranging from 9C in the winter months to 16C in August. As an exposed marine location, conditions can vary significantly, requiring careful planning and experience to navigate the coastal environment safely.