"Hissem" was brought out of reserve in 1955 and converted for use as a radar picket ship at Boston Navy Yard. Equipped with the latest electronic detection devices, she recommissioned at Boston 31 August 1956. After shakedown the ship joined the Atlantic Barrier, cruising as a sea extension of the DEW line to strengthen the northern defenses of Canada and the United States. In the years that followed, first out of Boston and later Newport, "Hissem" alternated 1 month of lonely picket duty with a month of in-port or training time, often experiencing the characteristic heavy weather of the North Atlantic. In 1959 and 1962 she made visits to Northern European and Mediterranean ports.