Wolfpacks U-421 was part of
U-421 operated with the following Wolfpacks during its career:
Coronel (4 Dec 1943 - 8 Dec 1943)
Coronel 1 (8 Dec 1943 - 14 Dec 1943)
Coronel 2 (14 Dec 1943 - 17 Dec 1943)
Föhr (18 Dec 1943 - 23 Dec 1943)
Rügen 6 (23 Dec 1943 - 26 Dec 1943)
Hela (28 Dec 1943 - 1 Jan 1944)