Rent U Boats at Sea (1994)

Brian Matthews narrates this documentary focusing upon the development of the German submarine prior to the outbreak of World War 2. The Treaty of Versailles had prohibited any development of the German military fleet, but this agreement was cancelled by the German-British naval treaty of June 1935. By the outbreak of war in 1939 Germany had 57 submarines ready for active service, though only 22 were capable of being deployed in the Atlantic.