Section 82(1)(a) in Bihar Inland Vessels Rules, 2013
(a)two mast head lights forward in a vertical line when the length of the two exceeds 200 meters; There such light in a vertical line. These lights will be in-lieu of light prescribed in rule 81 (1) (a). The lights shall be placed not less than 1 meter apart and the lowest light placed at a height not less than two meters above the hull.