The Site is based on an exposed underwater plateau, located five kilometres north of the Channel Island of Jersey. It comprises a sub-tidal reef characterized by kelp forests and animal turfs, and an intertidal zone dominated by rocks and boulders. The Site is rich in biodiversity, with 25 different biotopes and around 200 marine species recorded. Extensive shallow-water areas and numerous intertidal pools provide habitat and act as a nursery area to a wide range of fish and invertebrate species. Some species are regionally scarce, or globally vulnerable such as the green ormer (Haliotis tuberculata) and pink sea fan (Eunicella verrucosa). The Site is used by grey seals (Halichoerus grypus) which breed in the other Jersey Ramsar Sites, and is a foraging habitat for one of the largest breeding populations of bottlenose dolphin (Tursiops truncates) in the British Isles. The exposed reef also forms an important resting site for birds and feeding ground for seabirds. The area provides multiple ecosystem services: it contributes to an important commercial fishery for various shellfish and wet fish, is used extensively for recreational fishing, and in the summer is frequented by canoeists. It also plays an important role in offering biological resilience to the wider Bay of Granville region.