Your Certificate of Registry is not valid until you have your vessel marked according to requirements noted on the back of your Certificate of Registry:Name and Port of Registry:For pleasure craft and air cushion vehicles, both the name and port of registry must be marked together on a clearly visible exterior part of the hull.
For commercial vessels, the vessel name must be marked on each bow and the vessel name and port of the registry must be marked on the stern. If the vessel has a square bow, the name may be marked on a clearly visible exterior part of the bow. You may make the markings by any means and materials that result in durable markings. All must be at least 10 cm in height, made in clearly legible letters of the Latin alphabet or Arabic or Roman numerals
Registered tonnage and official number:Both the official number and registered tonnage shown on the Certificate of Registry must be marked in block-type Arabic numerals at least 4 cm high on a clearly visible interior structural part of the hull. Place the abbreviation:“N.R.T.” before the registered tonnage
“O.N.” before the official number
Note: Make sure these numbers are permanently affixed so that changes to, and attempts to remove or replace them would be obvious and cause some scarring or damage to the surrounding hull area.