Holyhead, Wales, United Kingdom

Holy Island Cliffs

The cliffs at the western edge of Holy Island, Anglesey, drop into some of the most dramatic underwater topography in North Wales. Vertical rock walls, gullies, caverns and pinnacles fall from the surface to over 25 metres on a clean rock and sand bottom, exposed to Irish Sea swell and strong tidal currents. Diving is concentrated around North Stack, South Stack and the cliffs that rise to the iconic South Stack lighthouse. The walls are densely encrusted with jewel anemones, plumose anemones, dead man's fingers, sponges, hydroids and kelp on the upper margins, with red and pink coralline algae carpeting horizontal surfaces. Resident fish include ballan wrasse, cuckoo wrasse, pollack, bib, conger eels, tompot blennies, lobsters and edible crabs. Atlantic grey seals are commonly seen on the surface and occasionally underwater near the gullies. Currents are strong off the headlands and dives are timed around slack water from Holyhead charter boats. Visibility ranges from 5 to 12 metres in summer, with water temperatures between 9 and 16 degrees Celsius. Suitable for advanced drift-experienced divers.