She departed her conversion yard on 22 October 1945 and soon proceeded to Guantanamo Bay, Cuba, for refresher training. Following post-shakedown availability, "William T Powell" trained in Casco Bay into late January 1946 and underwent a logistics period at Boston. She then sailed to Miami, Florida, where she joined the presidential yacht, , from 8 to 13 February before sailing for Norfolk. She later pushed on for Quonset Point, Rhode Island, on 31 March and, in April, plane-guarded for the escort carrier , in company with , in Narragansett Bay and off Norfolk and participated in fleet exercises at Guantanamo Bay and Culebra in May.