Vessel Marking Instructions
A documented vessel must be marked with its name, hailing port, and official number. Operation of a documented vessel without the proper markings violates United States Law. The exterior markings must be clearly legible letters of the LATIN ALPHABET and/or ROMAN or ARABIC NUMERALS of not less than FOUR inches in height.
BOW MARKINGS (Required for commercial vessels only)
The name of a vessel which is engaged in a trade must be marked on a clearly visible exterior part of both bows and on the stern of the vessel. For a vessel with a square bow, the name may be marked on some clearly visible exterior part of the bow in a manner to avoid obliteration. Recreational vessels need not have the name marked on the bow.
STERN MARKINGS (Required for both commercial and recreational vessels)
The vessel name and hailing port must be marked together on some clearly visible exterior part of the hull.
The six or seven digit Official Number awarded by the U.S. Coast Guard must be permanently affixed in block type ARABIC NUMERALS of not less than THREE inches in height on some clearly visible interior structural part of the hull in a manner so that removal, alteration, or replacement would be obvious. The number must be preceded by the abbreviation "NO." The Official Number may be marked on a separate plate, but it must be fastened in such a manner so that its removal would normally cause scarring of or damage to the surrounding hull area.