Demobbed from 'active' service, Cadet Midshipman Queasy has been spending the war as a seasick-remedy guinea pig in a research tank. To continue his career in the Navy, he buys a Victorian pier with a view to making it a seaside entertainment center. But the local councilors have other ideas for the R.M.S. (Really Motionless Ship) Arabella. A state of war is declared and the battle of Sandcastle Bay - unique in the annals of naval history - commences.