Sam Martin (Audie Murphy) owns a charter boat in the Florida Keys. He also has a serious gambling problem and mounting debts. His wife, Lucy (Patricia Owens), and first mate, Harvey (Everett Sloane), have managed to keep him out of serious trouble. However, when Sam suddenly finds himself on the brink of bankruptcy, he resorts to helping crooked weapons dealer Hanagan (Eddie Albert) smuggle guns into Cuba. But things get ugly for Sam when the scheme expands to include murder.