After commissioning in January 1929, Champlain was homeported in Stapleton, New York.[2]
As part of the Lend-Lease Act she was transferred to the Royal Navy where she was renamed HMS Sennen (Y21) and commissioned on 12 May 1941.[3] On 19 May 1943, Sennen assisted in the sinking of U-954 by depth charges. At the end of the war, in March 1946, she was returned to the USCG.[3]
Upon her return to the USCG, her original name was restored and she was given the hull number and designation WPG-319. She was then placed into reserve status until March 1948 when she was sold to Hughes Brothers, Inc. of New York.[2]