

Best for beginner divers, 10-25m, boat entry, mild current.
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.
54.46923, -8.44445
The shore entry involves surf and a shore break, so the boat approach is the sensible choice here. Watch conditions before committing, as swells on this stretch of coast can build quickly even on otherwise calm days.
Diving is by boat only. Launching in Mullaghmore is from the beach inside the harbour, with a slip leading down from opposite the Beach Head Hotel.
Recorded at this site
Depth
10-25m
Visibility
4-10m
Skill Level
Beginner
Entry
Boat
Boat required
Water Temp
9-16°C
Current
Mild
Typical Dive
40 min
Yes, the site is rated as suitable for beginner divers.
The reef reaches depths of 10 to 25 metres, with an average depth of 15 metres.
Boat access is required to reach the site, as the shore entry involves challenging surf and a shore break.
Visibility ranges from 4 to 10 metres, and currents are generally mild, though surface conditions can be affected by surf and swells.
Divers should be cautious of strong currents and surf conditions, which can change quickly.
Diving at Thumb Rock in Mullaghmore requires the following certifications: Open Water. Always dive within your training limits.
A drysuit recommended is recommended for diving at Thumb Rock in Mullaghmore. Water temperatures range from 9°C to 16°C.