In World War II the Royal Navy saw action in every one of the world's oceans. At the beginning of the war it was the largest navy in the world, and with Winston Churchill as the First Lord of the Admiralty, it was a fearsome opponent. From the Home Fleet base at Scapa Flow in the Orkneys, and the Mediterranean Fleet base at Alexandria, the sacrifice made by the Royal Navy during World War II was great: 5 capital ships, 10 carriers, 31 cruisers, and 146 destroyers. Over 50,000 of its personnel perished. With archive footage and computer graphic reconstruction, this programme shows a selection of the crucial battles and missions of the Royal Navy in World War II, including the Battle of the Atlantic, the Arctic Convoys, the Battle of the River Plate and the sinking of the Graf Spee. Also featured: the battle between HMS Hood and the Bismarck, and the story of Convoy ONS5, which proved that the Navy-escorted convoys were a match for the U-boat menace.