Originally covered in bitumen, this large alloy plaque has been cleaned up and restored to show U421 on active service. Such plaques were originally made or bought for someone in the Kriegsmarine and many have a piece of iron wire on the reverse for hanging. U421 was part of the 9th flotilla known as the Laughing Swordfish which included U96, featured in TV series Das Boot.
It was commissioned on 13th January 1943 under Leutnant zur See Hans Kolbus and took part in six group attacks on convoys in Dec of that year. The freighter with its back broken on the horizon may refer to one of these events. U421 ended its days in the French port of Toulon on 29 April 1944 when it was sunk during a USAF air raid.