The two vessels were kept in service until the German invasion of Norway in 1940. Glommen and Laugen operated in the area around Melsomvik, and surrendered to the Germans on 14 April 1940. The Germans rebuilt both of them as floating flak batteries, and renamed them Nki-01 and Nki-02.
Glommen was scuttled at Kirkenes by the retreating Germans in 1944, while Laugen was returned to the Royal Norwegian Navy in 1945, and decommissioned and sold for in 1950.