Gray seal (Halichoerus grypus) sleeping on the beach. The grey seal is a large seal that inhabits coastal waters in the North Atlantic, from New England in the USA through Canada, Iceland, and across the British Isles to Scandinavia. It feeds mainly on fish, although will take cephalopods, crustaceans and even seabirds. Males can reach over three metres in length and weigh more than 300 kilograms, females are much smaller. Filmed in Martin's Haven, Pembrokeshire, Wales, UK.