Carrick is a dirty British coaster - a 30-year-old tramp carrying unglamorous cargoes from port to port in the Channel and the North Sea. Her skipper and owner is Rick Waters , once part-time butler to Edward Heath: 'I resent people calling my ship a rust-bucket. She's an old lady who needs the occasional helping hand.' George Norman, the mate, looks after the cargoes. The ship could capsize if a cargo shifts at sea. Tom Owen, ex-Royal Navy, struggles with Carrick's dodgy engine. 'Most other merchant seamen regard coaster crews as the scum of the earth,' he says. Carrick makes uncertain progress through the mad March days, carrying fertilizer to Exmouth, grain to Antwerp, and spuds, improbably, to Wisbech. Coasters like Carrick can reach the ports that other ships can't....