What Is a Vessel Official Number?
Every vessel entered on Transport Canada's Canadian Register of Vessels is assigned a unique official number (O.N.). This applies to registered vessels — commercial vessels, vessels over 15 gross tonnes, and pleasure craft whose owners chose full registration instead of a Pleasure Craft Licence (PCL).
The official number is the vessel's permanent identity in the Register. It stays with the hull for the life of the vessel, even through name changes, port changes, and changes of ownership. It is marked on an interior structural part of the hull — not on the exterior — in a permanent, legible way (commonly an engraved or permanently affixed marking on a beam, bulkhead, or other structural member).
Name and Port of Registry — Exterior Marking
Registered vessels must display the vessel name and port of registry on the exterior of the hull. Transport Canada issues marking instructions with the certificate of registry; the standard scheme is:
Registered Vessel vs. Pleasure Craft Licence — Do Not Mix the Systems
Registered vessels (Canadian Register of Vessels)
Display the vessel name on each bow and the name with port of registry on the stern. The official number is marked inside the hull. Registered vessels do not display a PCL number.
PCL vessels (most recreational boats)
Display the Pleasure Craft Licence number on both sides of the bow, minimum 75 mm (3 in) block characters, in a contrasting colour, under the Small Vessel Regulations (SOR/2010-91). PCL vessels have no port of registry marking.
Which one is your boat?
If Transport Canada issued you a certificate of registry, you follow the registered-vessel scheme. If you hold a pleasure craft licence, you follow the PCL display rules. A vessel is in one system, not both.
Common Marking Mistakes
These are the marking problems we see most often on registered vessels:
- ✕Official number painted on the exterior hull — the O.N. belongs on an interior structural part
- ✕Vessel name on the stern only, with the bows left blank
- ✕Port of registry missing from the stern marking
- ✕Renamed vessel still showing the old name — exterior markings must match the Register
- ✕Low-contrast lettering (dark name on a dark transom)
- ✕Temporary materials — taped or magnetic lettering instead of permanent marking
- ✕Hull repainted a new colour with the old lettering left unreadable against it
Related Marine Guides
Registered Vessel Marking Checklist
Before the season, confirm each item:
- Vessel name marked on both bows in contrasting block letters
- Vessel name and port of registry marked on the stern
- Official number permanently marked on an interior structural part
- All exterior markings match the current certificate of registry exactly
- Lettering legible, unfaded, and not obscured by equipment or fenders
- Certificate of registry on board
One Kit for the Whole Marking Scheme
Vessel name, port of registry, and numbers in UV-rated marine-grade vinyl built to stay legible. Proof before production. Ships across Canada.