The Incredible Mr. Limpet

Don Knotts stars as a scrawny, milquetoast bookkeeper who longs to fight for the United States during World War II. But after the Army rejects him as unfit for military duty, he falls off a pier in Coney Island and discovers a magical undersea world when he becomes The Incredible Mr. Limpet. Henry Limpet (Knotts) amazingly learns he can breathe underwater and swim with the dolphins. He discovers love, the life he has always dreamed of and becomes a hero when he leads the Navy to a Nazi u-boat in this part-live action, part-animated family film.