USS War Bug (SP-1795) was a three-armed motorboat in commission in the United States Navy as a patrol vessel from 1917 to 1918. War Bug was built as the wooden-hulled motorboat Herreshoff 320 at Bristol, Rhode Island, in 1917 by the Herreshoff Manufacturing Company for a private owner, and probably was designed with possible naval service in mind. The U.S. Navy purchased Herreshoff 320 from Felix Warburg of New York City on 6 November 1917 for use as a patrol vessel in World War I. Armed and designated SP-1795, she was commissioned as USS War Bug on 17 November 1917.