A merchant name retained.
Mercurius, a single screw cargo steamer, was built by W. Hamilton & Go., Ltd., Port Glasgow, Scotland, in 1909. Prior to America's entry into World War I, she plied the sealanes between Europe and the United States. Operated by an Austrian firm under Dutch registry, she was seized by the U.S. Government at New York 20 March 1918; turned over to the Navy 19 April 1918; and commissioned there 30 April 1918, Lt. Comdr. C. L. Morris, USNRF, in Command.
Assigned to duty with NOTS, Mercurius steamed to Norfolk, loaded a cargo of mine supplies, and sailed for Europe 26 May. Arriving Lamlash, Scotland, 13 June, she unloaded cargo, thence returned to Norfolk 20 July. She made a second cargo run to Scotland and back in the closing months of World War I, and, after reaching Norfolk 15 November, carried supplies to the Canal Zone and back to New York between 2 and 27 December.
Mercurius departed New York for the eastern Mediterranean 16 January 1919 and carried 2,600 tons of food in support of the Turkish relief expedition. She operated in the Mediterranean from 14 February to 4 March, then, after returning to the United States 1 April, she loaded a cargo of European‑bound foodstuffs at Baltimore and sailed 28 May. Mercurius reached Rotterdam, Netherlands, in mid‑June and was ordered demobilized. She decommissioned 25 June 1919 and was returned to her owners, Konink., Nederl., Stoomb., Maats.
