The lights mentioned herein shall, if exhibited in pursuance
of Rule 26(d), be placed where they can best be seen. They shall be
at least 0.9 metre apart but at a lower level than lights prescribed
in Rule 26(b)(i) and (c)(i). The lights shall be visible all round
the horizon at a distance of at least 1 mile but at a lesser distance
than the lights prescribed by these Rules for fishing vessels.