She was assigned to the 5th Naval District and operated on inshore patrol duty out of Norfolk, Virginia, until 11 January 1944. Sailing to Boston, Massachusetts, Kestrel performed similar duties in the 1st Naval District. She was reclassified as Unclassified Miscellaneous Auxiliary Ship IX-175 on 10 July 1944 and operated for the remainder of her service as an experimental vessel for Radiation Laboratory, M.I.T., Cambridge, Massachusetts. Kestrel was placed out of service on 29 October 1945 and delivered to the War Shipping Administration for disposal on 5 August 1946