German weather ship Lauenburg

The Lauenburg was a German weather ship used in the early years of the Second World War to provide weather reports for German shipping, particularly German U-boats. Her capture and subsequent sinking on 28 June 1941 allowed the Royal Navy to acquire important German code books and parts of an Enigma machine, and came after the German use of such vessels had been identified as a weakness that could be exploited to break the Enigma code.

• http://en.wikipedia.org/wiki/German weather ship Lauenburg