Author: Ilker Temir - data by uboat.net

German U-boat losses and their locations in World War II

During World War II, U-boat (German submarines) warfare was the major component of the Battle of the Atlantic, which lasted the duration of the war. Prime Minister Winston Churchill would later write "The only thing that really frightened me during the war was the U-boat peril."

In the early stages of the war the U-boats were extremely effective in destroying Allied shipping due to the large gap in mid-Atlantic air cover. Cross-Atlantic trade in war supplies and food was extensive and critical for Britain's survival. The continuous action surrounding British shipping became known as the Battle of the Atlantic, as the British developed technical defenses such as ASDIC and radar, and the German U-boats responded by hunting in what were called "wolfpacks" where multiple submarines would stay close together, making it easier for them to sink a specific target. Britain's vulnerable shipping situation existed until 1942, when the tides changed as the U.S. merchant marine and Navy entered the war, drastically increasing the amount of tonnage of supplies sent across the Atlantic. The combination of increased tonnage and increased naval protection of shipping convoys made it much more difficult for U-boats to make a significant dent in British shipping. Once the United States entered the war, U-boats ranged from the Atlantic coast of the United States and Canada to the Gulf of Mexico, and from the Arctic to the west and southern African coasts and even as far east as Penang.

The most common U-boat attack during the early years of the war was conducted on the surface and at night. This period, before the Allied forces developed truly effective antisubmarine warfare tactics, which included convoys, was referred to by German submariners as "die glückliche Zeit" or The First Happy Time. As Allies developed more advanced technology and aircraft, from mid 1943 onwards, U-boat losses reached devastating levels for the Germans.

This map illustrates both the number and location of U-boats that were sunken during World War II in a 23 second animated image. Impact of Black May (1943) can be clearly seen in the visualization.

Data is obtained from uboat.net, an excellent project spearheaded by Gudmundur Helgason and supported by many others.

If you are interested in the history of U-boats, check out the following books: