Seaman's Handbook

ANNEX I. Positioning and technical details of lights and shapes

(a) The light indicating the direction of the outlying gear from a vessel engaged in fishing as prescribed in Rule 26 c
  1. shall be placed at a horizontal distance of not less than 2 metres and not more than 6 metres away from the two all-round red and white lights. This light shall be placed not higher than the all-round white light prescribed in Rule 26 c (i) and not lower than the sidelights.(b) The lights and shapes on a vessel engaged in dredging or underwater operations to indicate the obstructed side and/or the side on which it is safe to pass, as prescribed in Rule 27 (d) (i) and (ii), shall be placed at the maximum practical horizontal distance, but in no case less than 2 metres, from the lights or shapes prescribed in Rule 27 (b) (i) and (ii). In no case shall the upper of these lights or shaped be at a greater height than the lower of the three lights or shapes prescribed in Rule 27(b) (i) and (ii).