Here in BC, there is a free Vessel Licensing system, that results in a "BC number" that you can display on the bows of your boat. If you do this, you won't need to "Register" through the Canada Shipping Act. Just fill out a form and drop it off, out comes your new number.
In Canada, registration involves carving the "Official Number" into the "Main Beam" and having the boat measured, to get the "Registered tonnage". This information will tell how much coal can be carried for her majesty, should a state of war require the vessel to be requisitioned for military service.
Registration also eliminates the need for all those ugly numbers to be displayed, and gives you a "Blue Book" that contains one piece of paper, the "Certificate of Registration" which tells all the important things about the boat, length, breadth, depth, tonnage, distance from the front of the rudder post to the bow, ownership, mortgages, master, and maybe a few other things. The Registered name must be unique to your boat, including the whole country, so often, although you think yours is the only "Retreat" a search of the registry may turn up one in Halifax, another in Prince Rupert, so yours will need to take a number to be unique. Then the carved numbers and the displayed name have to be "viewed" by someone with appropriate credentials, RCMP or Coast Guard, Customs, Justice of the Peace, etc. and all appropriate fees paid. Last I looked, the fees were in the $250 to $300 range, not including any charges for affixing the name and numbers and the viewing.
Registration used to be mandatory if your vessel is over 12 meters, but recent changes (the intro of the free licensing system a few yrs ago) have changed that, so boats the size of mine and larger are frequently licensed now.
It is widely stated that Registration makes clearing into other jurisdictions easier, but I have no experience to relate.
In my view, you get exactly what you pay for.