In February 1965, "Barry" ventured south to the Caribbean for the annual spring training exercises and, in June, acted as assistant recovery ship for the Gemini 4 space shot. The balance of the summer, highlighted by her winning the Squadron Battle Efficiency "E" for ASW, was spent preparing for the destroyer's first Western Pacific deployment. As flagship of Destroyer Squadron 24 (DesRon 24), the first group of Atlantic Fleet destroyers to deploy to Vietnam, she departed Newport with , "Charles S. Sperry" (DD-697), , , and on 29 September. The Norfolk-based and "Bache" accompanied the squadron.