USS Breakwater (SP-681) was a United States Navy patrol vessel, minesweeper, and tug in commission from 1917 to 1920. Breakwater was built as a wooden-hulled, single-screw commercial steam fishing trawler of the same name at Milton, Delaware, in 1907. In the spring of 1917, the U.S. Navy purchased her from the Lewes Fishing Company of Lewes, Delaware, for use during World War I. Assigned the section patrol number 681, she was commissioned at the Philadelphia Navy Yard in Philadelphia, Pennsylvania, on 12 May 1917 as USS Breakwater (SP-681).