The submarine was ordered on 9 June 1937 and laid down on 12 October 1937 as K XXIII at the Rotterdamsche Droogdok Maatschappij, Rotterdam. During construction she was renamed O 23, and was finally launched on 5 December 1939. Following the German invasion of 10 May 1940, O 23 was hastily commissioned, still incomplete, and sailed for England on 13 May to be completed at the Thornycroft shipyard at Southampton.[2]
During the war she operated in the North Sea, the Mediterranean Sea and the Indian Ocean. O 23 made twenty patrols during the war in the course of which she sank or damaged five ships. She survived the war and was decommissioned on 1 December 1948, being sold for scrap in April of the following year.[2][3]
^ abHelgason, Guðmundur (2013). "HNMS O 23". uboat.net. Retrieved 25 July 2013.
Further reading
Drijfhout van Hooff, J.F. (December 1992). "De Meidagen van 1940"(PDF). Klaar Voor Onderwater (in Dutch). No. 41. Den Helder: Onderzeedienst Reünistenvereniging. pp. 4–12.
Drijfhout van Hooff, J.F. (March 1993). "De Meidagen van 1940 (II)"(PDF). Klaar Voor Onderwater (in Dutch). No. 42. Den Helder: Onderzeedienst Reünistenvereniging. pp. 3–9.