International regulations for preventing collisions at sea (1972)
ADDITlONAL SlGNALS FOR FISHING VESSELS
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.
2. Signals for trawlers
(a) Vessels of 20 metres of more in length when engaged in trawling, whether using demersal or pelagic gear, shall exhibit:
(i) when shooting their nets: two white lights
in a vertical line;
(b) Each vessel of 20 metres or more in length engaged in pair trawling shall exhibit:
(i) by night, a searchlight directed forward
and in the direction of the other vessel of the pair;
(c) A vessel of less than 20 metres in length engaged in trawling, whether using demersal or pelagic gear or engaged in pair trawling, may exhibit the lights prescribed in paragraphs (a) or (b) of this section, as appropriate.
3. Signals for purse seiners
Vessels engaged in fishing with purse seine gear may exhibit two yellow lights in a vertical line. These lights shall flash alternately every second and with equal light and occultation duration. These lights may be exhibited only when the vessel is hampered by its fishing gear.