Herm, Channel Islands, United Kingdom

Herm Channel Islands

Herm is a small island in the Channel Islands just east of Guernsey, surrounded by reefs, sandbanks and rocky outcrops that offer excellent intermediate diving in some of the clearest temperate water in the British Isles. The waters around Herm benefit from strong tidal currents through the channel between the island and Guernsey, supporting unusually rich marine life for a temperate location. Sites include Mouettes, Tete de la Pointe and Crevichon, with vertical walls, gullies and reef shelves descending from the surface to 25 metres on a clean rock and sand bottom. The walls are densely covered with jewel anemones in pinks, oranges and reds, plumose anemones, dead man's fingers, sponges, hydroids, pink coralline algae and kelp forests on the upper margins. Resident species include ballan wrasse, cuckoo wrasse, corkwing wrasse, pollack, bib, conger eels, tompot blennies, lobsters, edible crabs, spider crabs, cuttlefish in summer and Atlantic grey seals. Visibility commonly reaches 10 to 18 metres in summer, with water temperatures between 11 and 18 degrees Celsius. Currents are moderate to strong, with slack water timing required.