Actus, a 120-foot steam yacht, was built in 1907 at Neponset, Massachusetts. Her name was changed from Halawa at some point before World War I. The Navy apparently placed her in commission in April 1917 as USS Actus (SP-516), but did not formally purchase her until late May. For the rest of the First World War she served on patrol duties along the eastern coast of Massachusetts, and continued in service in the Boston area during the first months of 1919. USS Actus was decommissioned in July 1919. A year later, in July 1920, she was transferred to the War Department.