The German U-boats were a deadly force during World War II, striking fear into the hearts of Allied sailors and threatening to turn the tide of the war in favor of Nazi Germany. But despite their fearsome reputation, U-boats were not invincible, and Allied forces successfully sunk a large percentage of the vessels.

In this article, we take a closer look at the fate of the German U-boats and explore the question of how many of them were sunk during the war.

German submarines were nicknamed “U-boats” after the German word unterseeboot. Translated literally this means “under sea boat”.

The U-boat was one of the most feared weapons in the German arsenal in World War II. Their ability to appear out of nowhere and strike deadly blows then disappear again in a rapid succession proved devastating to allied plans in the Atlantic. U-boats decimated not only allied military vessels, but their commercial supply ships as well.

Given the German U-boats’ devastating impact early in the war, allied success hinged on neutralizing the threat.

How Many German U-boats Were Sunk in World War II?

By the end of the war the allies sunk 785 German U-boats out of a total of 1,162 total constructed during the war. The U-boats suffered particulaly heavy losses towards the end of the war from 1943-1945 after the allies adjusted the tactics. In May 1945 alone the allies sunk 108 German U-boats.¹

Furthermore, though the U-boats inflicted thousands of casualties to the allies in ships and loss of supplies, the own crews suffered greatly from the losses. At war end nearly 30,000 U-boat personnel were lost in action out of the 40,000 total naval crewman. The stunning casualty rate of over 75% is a truly frightful number.

At the onset of the war the U-boats proved extremely effective and lethal to British navy. Some historians believe the Destroyers for Bases deal in 1940, upon which the US sent 50 reserve destroyers to the British for access to British bases, was in part due to their fleet being decimated by German U-boats.

The allies changed their strategy to better cope with the U-boat threat as the war progressed. Convoys emerged that always had escorts to more easily find and eliminate the U-boat threat. In response, U-boats began to roam in groups, or “wolf packs” to more easily attack and sink these convoys.²

The allied success in cracking the German code used to communicate with U-boat crews also helped to aid in turning the tide of war.

Eventually radar technology improved enough to neutralize the stealthiness of U-boats. After nearly crippling the allied Atlantic supply lines, they lost effectiveness and were virtually nonexistent in the Atlantic by the end of the war (though were still active in other theaters).

Part of the reason the Normandy D-Day landings were so successful was due to the allies effectiveness in neutralizing the U-boat threat. Ultimately, the U-boats played an important role in Germany’s World War II strategy, though failed truly turn the tide of war.

Sources

1) Assmann, Kurt. “Why U-Boat Warfare Failed.” Foreign Affairs, vol. 28, no. 4, 1950, pp. 659–70. JSTOR, https://doi.org/10.2307/20030803.

2) Schofield, B. B. “The Defeat of the U-Boats during World War II.” Journal of Contemporary History, vol. 16, no. 1, 1981, pp. 119–29. JSTOR, http://www.jstor.org/stable/260619.