U-Boat sequence: various shots from conning tower, from another ship, of submarine at sea. Various interior shots of conning tower, of submarine itself, crew manning controls. LS of periscope moving through water. Shot through periscope of waves at periscope level, of ships. Shot of officer at periscope. PAN of ships in convoy seen individually. MCS of sailor releasing torpedo. CS of torpedo leaving submarine. MLS of wake of torpedo. Shots of explosion, of ship burning. Shot of another torpedo leaving tube, of wake of torpedo, of explosion. LS of ship sinking. Various shots of submarine emerging from water as seen from conning tower of another ship.