List of all U-boats




Ordered14 Oct 1941
Laid down31 Mar 1943 Deutsche Werft AG, Hamburg (werk 394)
Launched18 Nov 1943
Commissioned9 Feb 1944Kapt. z. S. Hermann Lessing
9 Feb 1944 - Mar, 1945  Kpt. Hermann Lessing
Mar, 1945 - 13 May 1945  Oblt. Helmut Wicke
2 patrols
9 Feb 1944-31 Aug 1944  31. Flottille (training)
1 Sep 1944-30 Sep 1944  11. Flottille (active service)
1 Oct 1944-8 May 1945  33. Flottille (active service)
SuccessesNo ships sunk or damaged

Surrendered on 13 May 1945 at Loch Eriboll, Scotland (Waller & Niestlé, 2010).

Post war information (see more post-war boats):
Allocated to the USSR by the TNC. Arrived Libau (Latvia) on 4 Dec 45 with RN Pennant No: N.26. Allocated to the Baltic Fleet on 13 Feb 46. Renamed B-26 on 9 Jun 49. To reserve on 17 Aug 53. Designated as combat training hulk KBP-33 on 15 Sep 52. Re-designated, as training hulk UTS-23 on 27 Dec 56. Struck from Soviet Navy list on 13 Jan 68. Broken-up for scrap in Riga (Latvia).

Final location

View the 2 war patrols

Previously recorded fate

  • Surrendered at Lough Foyle (Lisahally), Northern Ireland on 14 May, 1945.

Men lost from U-boats

Unlike many other U-boats, which during their service lost men due to accidents and various other causes, U-1231 did not suffer any casualties (we know of) until the time of her loss.

U-boat Emblems

We have 1 emblem entry for this boat. See the emblem page for this boat or view emblems individually below.


Media links

Hitler's U-boat War, Vol II

Blair, Clay

German U-Boat Losses During World War II

Niestle, Axel

U-Boat Operations of the Second World War - Vol 2

Wynn, Kenneth

As an Amazon Associate earns a commission from qualifying purchases.