St Davids, Wales, United Kingdom

Ramsey Sound

Ramsey Sound is the channel between Ramsey Island and the Pembrokeshire mainland near St Davids. It is renowned among British divers for its drift dives over rocky reefs and through narrow gullies, where strong tidal currents can exceed five knots at peak flow but produce nutrient-rich water and exceptional growths of soft corals, anemones and sponges. Diving is only practical during slack water windows, typically lasting 30 to 45 minutes. The vertical rock faces and gullies are densely covered with jewel anemones, plumose anemones, dead man's fingers, sponges, hydroids, pink coralline algae and kelp on the shallower edges. Atlantic grey seals are common in the sound and often interact playfully with divers. Resident fish include ballan wrasse, cuckoo wrasse, pollack, bib, conger eels and corkwing wrasse, with lobsters and edible crabs in the gullies. Visibility ranges from 4 to 10 metres, peaking on neap tides, and water temperatures vary between 9 and 16 degrees Celsius. Charter boats run from St Davids and Solva, suitable for advanced drift divers.