Battle of the Atlantic - Timeline
The Battle of the Atlantic was the longest battle of World War II. World War II lasted for a total of 2,075 days. The Battle of the Atlantic lasted for 2,073 of these. It started with the sinking of the passenger liner Athenia on the day Britain and France declared war on Germany.
At the start of the war both the Royal Navy and the Kreigsmarine were unprepared. Britain used the convoy system evolved during World War I for merchant shipping but the RN did not have enough escort ships and aircraft. The Kreigsmarine had few battleships and cruisers. Only 39 of its U-boats were operational.
At the outbreak of war the only real threat to shipping was from surface raiders including the pocket battleships Deutschland and Admiral Graf Spee.
View the timeline : 1939 | 1940 | 1941 | 1942 | 1943 | 1944 | 1945