Check this link on plaque and boat marking requirements.
vesselplacards.com
vesselplacards.com

What Is USCG Documentation Number Placard?| Vessel Placards
USCG documentation number placard is a plaque that you should attach to your documented ship. This documentation number works like a Social Security number.

Vessel Placards Offers USCG Official Number Plates for Boats, Yachts & Ships
We are Vessel Placards, the web's leading number plate emporium. We offer a wide range of placard options to serve all of your nautical needs.
