German submarine U-68 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 20 April 1940 at the AG Weser yard at Bremen as 'werk' 987 launched on 22 October and commissioned on 1 January 1941 under the command of Korvettenkapitan Karl-Friedrich Merten as part of the 2. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
Mean Of Transportation