Alert, a 75-foot motor pleasure boat, was built in 1913 at Neponset, Massachusetts. Leased by the Navy in May 1917, she was commissioned later in that month as USS Alert (SP-511) and assigned to patrol duty along the New England coast. In April 1918 she was renamed SP-511 to avoid confusion with another USS Alert. The craft was decommissioned in November 1918, shortly after the end of World War I's fighting, and was soon returned to her owner.