SM UC-90

SM UC-90 was a German Type UC III minelaying submarine or U-boat in the German Imperial Navy (Kaiserliche Marine) during World War I. The U-boat was ordered on 12 January 1916 and was launched on 19 January 1918. She was commissioned into the German Imperial Navy on 15 July 1918 as SM UC-90. As with the rest of the completed UC III boats, UC-90 conducted no war patrols and sank no ships. She was surrendered to Japan on 1 December 1918. The U-boat was renamed O-4 for Japanese service from 1920 to 1921. In 1921 O-4 was partially dismantled at the Kure Navy Yard. Between 1924 and 1926, the hulk of O-4 was used as an antisubmarine warfare target before being sold for scrap.