The sailors were crew members of the U.S. Navy's Guided-Missile Destroyer, USS Halsey [DDG 97], that was visiting Chennai.
It was one of the American warships that took part in 'Exercise Malabar 2012', the primarily Indo-American Naval Exercise, with periodic participation from other countries. The ship receiving the salute is Indian Navy's latest Shivalik-Class Frigate, incorporating stealth characteristics, the
INS Sahyadri [F49] INS Satpura [F48]. The ship was commissioned into service on July 21, 2012 August 20, 2011.