A 50 minute documentary covering in essence the 'War in the Atlantic' and not just the 'Convoy System'. A constant battle between the British and her Allies to defeat the Kreigsmarine for control of the vast Atlantic crossing, which would become so vital for ultimate victory. Lots of info to digest, Technical - ASDIC, Huff Duff, Enigma etc (although not in great detail), types of craft, U-boats (type VII, snorkel), Planes (Sunderland, FW Condor) and Ships (Tirpitz, Bismarck, Hood) etc. Copious original footage with input from military historians and veterans. Not the best, but a good introduction and an interesting and educational film all the same.