Published in fifteen volumes, Morison provides a clear & detailed view of American efforts to keep transport lanes open, German reluctance to allocate major resources to the war at sea, & the influence on strategy of what each side thought the other capable. Volume I: The Battle of the Atlantic, September 1939- May 1943 concerns Allied efforts to protect shipping, supply, & troop transport against Axis submarines & their supporting aircraft & ships.

The Campaign in the Atlantic from the USN point of view.September 1939 to May 1943. This is Vol.I of USN in WWII. Morison was writing very close to the end of the war, in 1947, to be exact, and so this account has no mention of Ultra or a good deal else, with only a small amount of input from German sources. Still, invaluable information about the switch from the pre-War navy and the grudging change in emphasis to an Atlantic rather than Pacific war that the Navy had prepared for. ( )