|Ordered||20 Jan 1941|
|Laid down||8 Apr 1942||Howaldtswerke AG, Kiel (werk 25)|
|Launched||15 May 1943|
|Commissioned||3 Jul 1943||Oblt. Alfred Radermacher|
|Successes||No ships sunk or damaged|
Attacked on 4 May, 1945 in Gelting Bay in position 54.53N, 09.37E by aircraft from 9. USAAF XXIX TAC. 2 dead, unknown number of survivors. (Axel Niestlé, February 1990).
Scuttled on 5 May, 1945 in position 55.34N, 09.49E, near Fyn Islands in Flensburger Förde, position unknown.
Men lost from U-boats
Unlike many other U-boats, which during their service lost men due to accidents and various other causes, U-393 did not suffer any casualties (we know of) until the time of her loss.