Ranger was built as the steam-driven, steel-hulled yacht Thomas Slocum by Robert Jacob Shipyard at City Island, Bronx, New York, in 1910.

Slocum of New York City, on 22 June 1917 for World War I service as a patrol vessel and commissioned her as USS Ranger (SP-237) on 9 October 1917.

Assigned to the 3rd Naval District, Ranger operated as a section patrol craft in the New York City area.

SP-237 was decommissioned on 28 April 1919 and transferred to the Department of Commerce for use by the United States Coast and Geodetic Survey.

She served with the department as USC&GS Ranger until either 26 November 1930[3] or 31 January 1931,[4] when she was returned to the U.S. Navy.