Calvin B. Marshall (Paul Douglas), a wealthy American, plans to surprise his wife with a summer residence in the British Isles. Arrogantly certain that he can make a shrewd deal, he charters a small, rundown transport boat, "The Maggie," to carry his furnishings to the new property. Pilot Capt. McTaggert (Alex Mackenzie) desperately needs the job to save his boat -- but he and the crew of two men and a boy nevertheless plan to get the most out of Marshall on their most unorthodox journey.