Section 21(b) in Prevention Of Collision On National Waterways Regulations, 2002
(b)"Sidelights" means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 metres in length the sidelights may be combined in one lantern carried on the fore and aft centerline of the vessel. Sidelights shall be placed not less than 1 metre below the mast headlight.
