50 CFR 600.503 - Vessel and gear identification.
(1) The operator of each FFV assigned an IRCS must display that call sign amidships on both the port and starboard sides of the deckhouse or hull, so that it is visible from an enforcement vessel, and on an appropriate weather deck so it is visible from the air.
(2) The operator of each FFV not assigned an IRCS, such as a small trawler associated with a mothership or one of a pair of trawlers, must display the IRCS of the associated vessel, followed by a numerical suffix. (For example, JCZM-1, JCZM-2, etc., would be displayed on small trawlers not assigned an IRCS operating with a mothership whose IRCS is JCZM; JANP-1 would be displayed by a pair trawler not assigned an IRCS operating with a trawler whose IRCS is JANP.)
(3) The vessel identification must be in a color in contrast to the background and must be permanently affixed to the FFV in block Roman alphabet letters and Arabic numerals at least 1 m in height for FFV's over 20 m in length, and at least 0.5 m in height for all other FFV's.
(b)Navigational lights and shapes. Each FFV must display the lights and shapes prescribed by the International Regulations for Preventing Collisions at Sea, 1972 (TIAS 8587, and 1981 amendment TIAS 10672), for the activity in which the FFV is engaged (as described at 33 CFR part 81).
(ii) Has attached a light visible for 2 nautical miles (3.70 km) at night in good visibility.
(iii) Has a radio buoy.
Trawl codends passed from one vessel to another are considered continuously attached gear and are not required to be marked.
(2) The operator of each FFV must ensure that deployed longlines, strings of traps or pots, and gillnets are marked at the surface at each terminal end with: (see paragraphs (c)(1)(i) through (c)(1)(iii) of this section).
(3) Additional requirements may be specified for the fishery in which the vessel is engaged.
(d)Maintenance. The operator of each FFV must -
(1) Keep the vessel and gear identification clearly legible and in good repair.
(2) Ensure that nothing on the FFV obstructs the view of the markings from an enforcement vessel or aircraft.
(3) Ensure that the proper navigational lights and shapes are displayed for the FFV's activity and are properly functioning.