The Buoy Barnacle (Dosima fascicularis) lives in the warmer waters of the Atlantic and Pacific oceans, either producing their own 'float' from a spongy secretion from modified cement glands, or attaching themselves to larger objects. Often other barnacles also attach themselves to the same object, forming large colonies.
Although their home is in the ocean, they are sometimes stranded in large numbers along the west coasts of Britain and Ireland as a result of south-westerly winds.
This particular animal was attached to the side of a rockpool on Wembury beach, near Plymouth in Devon, in June 2007.