A 'fisherman's' type of anchor lying off the coast of Kythira, Greece. The design and degree of corrosion visible indicates that this anchor may be several hundred years old. An anchor is a device, normally made of metal, used to connect a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drogue, not in contact with the seabed, used to control a drifting vessel. Caustic rays from the sun are visible streaking from top left. These rays are caused by light being refracted by surface ripples