On 15 March 1947, "U-2513" headed north from Key West, Florida, bound for the New England coast, and arrived at Portsmouth, New Hampshire, on 22 March. She remained there until 8 September when she began six weeks of operations out of Portsmouth and New London, Connecticut, under the auspices of the Commander, Submarines, Atlantic Fleet. She concluded that duty on 15 October and departed New London to return to Key West. "U-2513" resumed her old duties at Key West five days later and continued them until the summer of 1949.