In company with DesDiv 161, "Ault" departed Mayport on 7 February 1967, transited the Panama Canal on 12 February, and stopped at Pearl Harbor, Midway, and Yokosuka before joining the 7th Fleet on 11 March. After a short period of ASW drills with near Subic Bay, she steamed with to station in the Gulf of Tonkin for plane guard duties. On 16 April, the destroyer was assigned to Task Unit 77.1.1 for Operation Sea Dragon, offensive surface operations against waterborne logistic craft and coastal defense sites in North Vietnam. As part of this unit, she joined , , and in conducting sweeps from Cap Lay north to Thanh Hóa.