SM U-90 was a Type U 87 u-boat of the Imperial German Navy during World War I. Its commander Walter Remy made regular stops at remote island North Rona for provisions such as fresh mutton. On 15 May 1918, U-90 shelled the Hirta wireless station in St Kilda, Scotland. On 31 May 1918, U-90 torpedoed and sank USS President Lincoln, a former Hamburg America Line steamer that seized by the United States for troop transportation. From the U.S.