Battlefield (1994)

The convoys that sailed across the Atlantic Ocean bringing vital supplies to Britain faced one of the most deadly threats of the war. Hidden deep beneath the waves were German U-boats. This program follows the evolution of the Atlantic War, from the beginnings of the U-Boat war, to the "Happy Time" when German submarines almost brought Britain to her knees, to the eventual Allied triumph for control of the Atlantic sea-lanes. Also see the critical role that superior Allied technology played in winning the war and how British cryptographers successfully broke the German naval codes.