AIR TO AIR SHOT of Argus aircraft flying low over water. LS of submarine conning tower. SEA TO AIR SHOT of Canso flying boat. MSs of radar scope, of man at control in submarine, of periscope ploughing water, of crew in Argus aircraft. Low AERIAL SHOTs submarine on surface of water. Several interior shots of Neptune aircraft, crew at work tracking submarine. Shots of radar scope intercut with shots of various crewmen. MLS of Neptune aircraft flying low over water.