Marking a documented boat: name, hailing port and official number
Registration & documentation · Power & sail
A boat documented for recreation shows its name and hailing port together on the outside of the hull in letters at least 4 inches high, and its official number, after 'NO.', in numerals at least 3 inches high inside. The certificate isn't valid for operation until the boat is marked (46 CFR 67.120, 67.121, 67.123).
- The markings must stay clearly visible. If a dinghy or gear routinely hides the transom, consider repeating the name and hailing port elsewhere on the hull (BoatUS guidance).
- A documented boat shows its name and hailing port outside and its official number inside. It must not also show a state registration number (46 CFR 67.123; 33 CFR 173.33).
Name and hailing port (outside)
- On a boat documented only for recreation, mark the name and hailing port together on some clearly visible exterior part of the hull; many owners use the transom (46 CFR 67.123(c); BoatUS).
- Letters must be clearly legible and at least 4 inches high, using the Latin alphabet or Arabic or Roman numerals, made with any means and materials that give a durable marking (46 CFR 67.123(d)).
- The hailing port must be a place in the United States and must include its state, territory or possession (46 CFR 67.119).
Official number (inside)
- Mark the official number, preceded by 'NO.', in block-type Arabic numerals at least 3 inches high on a clearly visible interior structural part of the hull (46 CFR 67.121).
- It must be permanent, so that altering or removing it would be obvious. If it is on a separate plate, the plate must be fastened so that removing it would normally scar or damage the hull around it (46 CFR 67.121).
Before you operate
- A new or exchanged certificate is not valid for operating the boat until the boat is marked (46 CFR 67.120, 67.141(c)).
- The owner must not let the boat be operated unless it is properly marked, and failing to maintain the markings can get the boat deleted from documentation (46 CFR 67.331, 67.171(a)(8)).
Changing the name or hailing port
- You need prior approval from the National Vessel Documentation Center to change a documented boat's name (46 CFR 67.117(c), 67.329).
- A name must use Latin letters or Arabic or Roman numerals, must not match or sound like words used to call for help at sea, and must not be obscene or a slur (46 CFR 67.117(b)).
- Changing the name or hailing port makes the certificate invalid immediately. Apply for an exchanged certificate, and mark the new name on the boat once you receive it (46 CFR 67.167(b), 67.329).
The rules: 46 CFR 67.117 · 46 CFR 67.119 · 46 CFR 67.120 · 46 CFR 67.121 · 46 CFR 67.123 · 46 CFR 67.141 · 46 CFR 67.167 · 46 CFR 67.171 · 46 CFR 67.329 · 46 CFR 67.331 · 33 CFR 173.33
Sources (4)
A plain-language summary of federal rules for recreational boats, checked against the rules’ own text and a second source, and written in our own words. It isn’t legal advice. States add rules of their own, and rules change — the links above go to the current official text.