 Medusa served in all three German navies over the span of over forty years . She served as a fleet scout in the period before World War I , and during the first two years of the conflict , she was used as a coastal defense ship . She was one of six cruisers Germany was allowed to keep by the Treaty of Versailles , and she served in the early 1920s in the Reichsmarine . She was withdrawn from service in 1924 and used in secondary duties , but in 1940 , the Kriegsmarine converted Medusa into a floating anti @-@ aircraft battery . She defended the port of Wilhelmshaven until the closing days of the war , when she was scuttled by her crew . The wreck was ultimately broken up for scrap in 1948 – 1950 . 
