From 1 February 1928, "Medusa" began to serve as a barracks ship for torpedo boat and destroyer crews in Wilhelmshaven. On 29 March 1929, she was stricken from the naval register. In July 1940, during World War II, "Medusa" was converted into a floating anti-aircraft battery at the Rickmers Reederei shipyard in Bremerhaven. Her armament at that point consisted of one &lt;a href="10.5%20cm%20SK%20C/32%20naval%20gun"&gt;10.5 cm SK C/32 gun&lt;/a&gt;, four &lt;a href="10.5%20cm%20FlaK%2038"&gt;10.5 cm SK C/33 guns&lt;/a&gt;, two &lt;a href="3.7%20cm%20SK%20C/30"&gt;SK C/30 guns&lt;/a&gt;, and four Flak guns. She was then assigned to Naval Anti-aircraft Group 222, and remained in the harbor at Wilhelmshaven, anchored off Varel, beginning on 13 August 1940. She remained there for the duration of the war. On 19 April 1945, she was badly damaged by an Allied air attack that killed twenty-three and wounded forty-one of her crew. Her remaining crew scuttled the ship on 3 May, days before the end of the war in Europe. British occupation troops found the wreck lying next to the . The wreck was ultimately salvaged in 1948–1950 and broken up for scrap.