Barnacle Bill stars Alec Guinness as Captain William Ambrose, a man who comes from a long line of distinguished sailors. He, however, is prone to seasickness. Ambrose settles down in the coastal town of Sandcastle-on-Sea, where he purchases an almost derelict amusement arcade at the pier. Ambrose plans to renovate the arcade, much to the dismay of the local council, who are under the impression the Captain wants to open a gambling house. The council opposition leads Ambrose to have to plot a course avoiding their pesky land laws.