|Ordered||14 Feb 1940|
|Laid down||3 Jul 1941||Deutsche Werft AG, Hamburg (werk 336)|
|Launched||17 Mar 1942|
|Commissioned||3 Jun 1942||Oblt. Klaus Bargsten (Knights Cross)|
|Successes||3 ships sunk, total tonnage 19,551 GRT|
1 auxiliary warship sunk, total tonnage 750 GRT
Attacks on this boat
31 Oct 1942
While attacking convoy SC 107 a Hudson aircraft (Sqdn 145) attacked the boat causing minor damage. (Sources: Blair, vol 2, page 45.)
1 recorded attack on this boat.
Men lost from U-boats
Unlike many other U-boats, which during their service lost men due to accidents and various other causes, U-521 did not suffer any casualties (we know of) until the time of her loss.