50 CFR 300.35: Vessel and gear identification.

While a vessel is in the Licensing Area, a Limited Area closed to fishing, or a Closed Area, a recent and up-to-date copy of the International Code of Signals (INTERCO) shall be on board and accessible at all times. The operator shall comply with the 1989 Food and Agricultural Organization standard specifications for the marking and identification of fishing vessels. The international radio call sign of the vessel shall be painted in white on a black background, or in black on a white background, and be clear, distinct, and uncovered, in the following manner:

(a) On both sides of the vessel's hull or superstructure, with each letter and number being at least 1 m high and having a stroke width of 16.7 cm, with the background extending to provide a border around the mark of not less than 16.7 cm.

(b) On the vessel's deck, on the body of any helicopter and on the hull of any skiff, with each letter and number being at least 30 cm high, and having a stroke width of 5 cm with the background extending to provide a border around the mark of not less than 5 cm.

(c) On any other equipment being carried by and intended to be separated from the vessel during normal fishing operations, with each letter and number being at least 10 cm high and having a stroke width of 1.7 cm, with the background extending to provide a border around the mark of not less than 1.7 cm.