Wiki article about the last Imperial German Navy warship still steaming

[Kaleva]

It's now being used as a ferry boat.

"Graf von Goetzen was built in 1913 in Germany, and was one of three vessels the German Empire used to control Lake Tanganyika during the early part of the First World War. Her captain had her scuttled on 26 July 1916 in Katabe Bay during the German retreat from Kigoma. In 1924, a British Royal Navy salvage team raised her and in 1927 she returned to service as the Liemba. Liemba is the last vessel of the Kaiserliche Marine still actively sailing anywhere in the world.

Liemba was the inspiration for the German gunboat Luisa in C. S. Forester's 1935 novel The African Queen, and John Huston's subsequent film version. Giles Foden retold the story.[1] The ship featured in the 1992 BBC Television travel series Pole to Pole and Michael Palin stayed in one of her cabins. Breadbox Productions in the US released a feature documentary film on the ship Liemba, narrated by Chiwoniso Maraire, in 2010."

http://en.wikipedia.org/wiki/MV_Liemba