List of all U-boats




Ordered23 Dec 1939
Laid down1 Dec 1940 AG Weser, Bremen (werk 1011)
Launched22 Jul 1941
Commissioned25 Oct 1941Oblt. Günther Pfeffer
25 Oct 1941 - 9 Oct 1942  Kptlt. Günther Pfeffer
1 patrol
25 Oct 1941-30 Jun 1942  4. Flottille (training)
1 Jul 1942-9 Oct 1942  10. Flottille (active service)
Successes3 ships sunk, total tonnage 17,641 GRT

Sunk at 1300hrs on 9 Oct 1942 in the Bay of Biscay near Lorient, France, in position 47.39N, 03.34W, by mines. 22 dead and 30 survivors.

Loss position

See the 3 ships hit by U-171 - View the 1 war patrol

The wreck of this boat has been discovered in position 47.39.532N, 03.34.778W.

This boat is a dive site

Near Lorient and Isle de Groix at 40m depth.

Depth: 120 feet (37 meters)
Position (lat, long): 47.39, -3.34

See more U-boat dive sites.

Attacks on this boat and other events

1 Aug 1942

An attack on 1 Aug. 1942 in the Gulf of Mexico in position 28.37N, 90.45W by a US Grumman J4F-1 aircraft (V-212 USCG/Y) was credited with sinking U-166 with a single depth charge.

However, U-166 was sunk the day before. The target may have been U-171.

(Sources: 2001-06-01,

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-171 did not suffer any casualties (we know of) until the time of her loss.

Media links

U-Boat Operations of the Second World War - Vol 1

Wynn, Kenneth

German U-Boat Losses During World War II

Niestle, Axel

Hitler's U-boat War

Blair, Clay

Torpedoes in the Gulf

Wiggins, Melanie