Lexington II was built as a private motorboat of the same name in 1911 by the New York Yacht, Launch & Engine Company at Morris Heights in the Bronx, New York.

On 13 July 1917, the U.S. Navy chartered her from her owner, Dale B. Fitler of Philadelphia, Pennsylvania, for use as a section patrol boat during World War I.

Delivered to the Navy on 22 July 1917, she was commissioned as USS Lexington II (SP-705) on 23 July 1917 at Camden, New Jersey.

She was enrolled in the Naval Coast Defense Reserve on 26 July 1917.

Assigned to the 4th Naval District and based at Philadelphia, Lexington II served on patrol duties for the rest of World War I.