"William T. Powell" operated with one of her former World War II cohorts, , in Casco Bay later that summer and off New London served as a target vessel for submarines from 13 to 30 September. She arrived at Newport, Rhode Island, on 30 September, moored alongside for a three-week tender availability, and subsequently departed Newport on 22 October, bound for Casco Bay where she arrived the same day. She conducted Navy Day observances there on the 27th before she transited the Cape Cod Canal and arrived at New London on 12 December. She spent the remainder of the year operating on training evolutions with submarines.