Did you know that the Bismarck, unlike all other ships in the Kriegsmarine, was not a she. We have to talk about the German language which has 3 articles instead of the as in English: Der(masculine) ,Die(feminine) Das(Neutral). All ships of the German navy are female for example the Tirpitz the lone queen of the north.

Filmmaker | History and Sim Racing lover  

Interesting question, unlike cruisers or battleships, submarines don't get special names. The U boat types were labeled according to their development, e.g. Type I - Type IX. These types were then given call names like U99 (Typ VIIB)or U103 (Typ IXB). The most successful submarine was U48 (Type VIIB) which sank 52 targets with a total of 307,935 gross register tons