RMO was a Norwegian clandestine organization for naval intelligence during World War II, led from Oslo. The organization operated from Spring 1942 until the end of the war in the spring of 1945.
RMO was established by Kapteinløytnant Andreas Rygg, as an initiative from naval attaché Hans Henriksen at the Norwegian legation in Stockholm. Because of the German mass arrest of Norwegian military officers in 1943, Rygg fled to Sweden, and the organization was subsequently led by Martin Siem and Sigurd Sverdrup.
RMO's primary goal was to establish contacts in the cities along the Norwegian coast. The contact persons were typically harbourmasters, maritime pilots and other sea workers or harbour workers. Siem and Sverdrup had earlier cooperated with Gunnar Sønsteby, and this cooperation continued after RMO was formed. RMO used Sønsteby's courier network to bring messages to Stockholm, and Sønsteby's organization ob