an Entity references as follows:
The German submarine U-6 was a long-lived but very inactive Type IIA U-boat built before World War II for service in Nazi Germany's Kriegsmarine. As she was one of the first batch of boats built following the renunciation of the Treaty of Versailles, she was capable of only coastal and short cruising work. This led to her being reassigned to training duties after the Norwegian campaign in 1940.