Section 6(4) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(4)Whenever the President shall be embarked in a ship or vessel at sea and the before-mentioned flags shall be hoisted in her, every one of Indian Naval Ships, meeting, passing or being passed by her, shall fire a [21 gun] [Substitued by S.R.O. 215, dated 4th May, 1974] salute.
