German submarine U-1004 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II.She was laid down on 15 January 1943 by Blohm & Voss, Hamburg as yard number 204, launched on 27 October 1943 and commissioned on 16 December 1943 under Oberleutnant zur See Hartmuth Schimmelpfennig.