USS Helvetia, a 499-ton three-masted schooner, was built at Rockland, Maine, in 1905 as the civilian vessel Helvetia. She was purchased by the Navy in July 1918 and subsequently used as a decoy ship. It was expected that her innocent mercantile appearance would draw German submarines to the surface to make an easy gunfire attack. The unsuspecting U-boats would then be easy prey for a U.S. Navy submarine lurking submerged nearby. Helvetia apparently made active patrols for this purpose, but no U-boats rose to the bait. She reportedly was also employed as a submarine stores and mother ship at Norfolk, Virginia, and New London, Connecticut. Helvetia was sold back to her former owner in March 1919.