Originally constructed in Leith, Scotland and launched as the civilian yacht Agawa on 20 September 1906, she was subsequently leased from William L. Harknessby the US Navy in 1917 and commissioned as the USS Cythera (SP-575). Sailing from New York on 27 October 1917, Cythera arrived at Newport the next day and was assigned to Patrol Force, Atlantic Fleet. She cleared Newport 1 November with her squadron, and escorted and towed submarine chasers to European waters, before arriving at Gibraltar on 29 December. Based out of Gibraltar, she patrolled and escorted convoys between her base and Mediterranean ports in France, Italy, and Africa. She was decommissioned 17 March 1919, and returned to her owner two days later.