Margin was built as a private motorboat of the same name in 1917 by W. E. Haff at Neptune Island, New York. On 6 December 1917, the 3rd Naval District inspected her for possible naval service, and on 21 March 1918 the U.S. Navy acquired her under a free lease from her owner, W. D. Hatch of Neptune Island, for use as a section patrol boat during World War I. She was commissioned as USS Margin (SP-2119 or ID-2119) on 28 June 1919. Assigned to the 4th Naval District, Margin served on patrol duty for the rest of World War I. The Navy returned her to Hatch on 1 April 1919.