Regulations for the Navy Part IIICentral Regulations · 1957
(1) Ships and vessels (including boats and launches using inland waterways) employed in the service of any public office in India wear a blue ensign, and a smaller blue ensign as a jack, but in the centre of the fly of such ensign and jack shall be inserted the badge of the office to which they belong. If a department or local Government has no distinctive badge, the Government of India crest, namely, 3 Asoka Lions, may be inserted in the flag.
(2) Ships and vessels employed in the service of the Indian Air Force shall wear the Indian Air Force ensign in place of the blue ensign described above.