Upon detachment from "Seahawk," "Whipple" stopped at Subic Bay for maintenance prior to proceeding to the Gulf of Tonkin to relieve the destroyer as Positive Identification and Radar Advisory Zone (PIRAZ) ship. After taking up station on 28 February, "Whipple" performed escort duties besides conducting her regular patrols. Her PIRAZ work during this time was light, as reduced air activity over North Vietnam was accomplished by low visibility and a cancellation of many scheduled flights. While "Whipple" operated in company with the destroyer on PIRAZ duties, the escort ship's electronic "eyes" maintained the air "picture" for the northern half of the Gulf of Tonkin. The destroyer escort next took up plane-guard duties for the carrier before providing gunfire support in Military Region 1 for the South Vietnamese Army's 3d Division. "Whipple" conducted 52 missions and expended 2,361 rounds of 5-inch ammunition.