How are you transporting the boat? There's a few things you need to think about there; for example if it's by land you'll need to properly prepare the boat for transport - check height restrictions, trailer ratings, vehicle hookups, etc. If by sea you need to make sure you have the correct safety gear on board because the rules and standards are different in Canada.
You also have to ensure you are buying a boat with a clear title (assuming this is a used boat?) - this process is not always straightforward and a good third party broker can be a big help here.
I've actually written an ebook on the process (contact me if you'd like info). I'm not looking to make a bunch of money, but since I know a lot about importing and have been involved in plenty of boat importations I decided to gather all this information and put it together into a single package.
Hope that helps!