The U.S. Navy purchased her on 15 June 1898 for use as a patrol yacht in the Spanish–American War.

In 1909, the Navy loaned Elfrida to the North Carolina Naval Militia.

She arrived at New Bern, North Carolina, on 26 July 1909 and was recommissioned on 20 August 1909.

After the United States entered World War I on 6 April 1917, Elfrida was returned to the Navy, which gave her the section patrol number 988 and put her into service as the section patrol boat USS Elfrida (SP-988).

Assigned to the 5th Naval District, she was placed in charge of a fleet of Navy motorboats tending the submarine nets at the York River Upper Barrier in Virginia.