Polarbjørn (‘Polar Bear’) was launched at Narvik in 1919, having been constructed for work in the Arctic. In 1923 she was the expedition ship for Adrian Jacobsen's expedition to Franz Josef Land, Svalbard, and Novaya Zemlya. The following year she was the expedition ship for George Binney's Oxford University expedition to Svalbard. She sailed twice to the Arctic with aeroplanes onboard to chart the region, in 1924 to Svalbard and in 1932 to northeast Greenland. Between 1931 and 1948 she was expedition ship for 10 scientific expeditions to Svalbard, Jan Mayen, and northeast Greenland organized by the Norges Svalbard-og Ishavsundersøkelser, the forerunner to the Norsk Polarinstitutt. In 1940 Polarbjørn was engaged by the Norwegian government in exile in London to deliver equipment and supplies to wintering trappers and wireless operators and to bring secret codes to the telegraph stations in northeast Greenland. From autumn 1941 to the end of the war she was chartered by US government forces and shuttled between Boston and Halifax to Greenland, Baffin Island, and Labrador. After the war she returned to sealing under Norwegian ownership, and in 1949 caught fire and sank off Belle Isle, Newfoundland.