Captain Ambrose comes from a long line of distinguished sailors, but is all too susceptible to seasickness. After the war, he buys himself a nautical command on shore, a decrepit amusement pier at the British resort town Sandcastle-on-Sea, whose prim town council has outlawed arcade games as a form of gambling. Running the pier like a Naval vessel, the Captain's determination to make it a modern, going concern meets steady opposition. But with an unexpected new ally, he pursues a remarkable scheme to liberate his "ship" from land authorities.