The second phase of the Battle of the Atlantic in 1942-1945 was characterized by taking the initiative by the Allies. Within the frameworks of this offensive, aircraft carriers which were able to dominate the sea battlefield, became the main force of the British and American fleet. Not only did they force the German submarines of the Atlantic to retreat but they also contributed to a defeat of above-water forces of Kriegsmarine. At the same time, without a support of aircraft carriers, it is difficult to imagine an operation of transferring soldiers and military supplies from the USA to Great Britain and as the effect opening in 1944 the second front in Normand, held so dextrously. Development of aircraft carriers and their active usage let the Allies win the Battle of the Atlantic faster and more dextrously.