If you sell a boat to someone in canada, due they have to pay tax to get it across border?

go to the source- us and can, gov'ts. make sure you are paid with good 'ole us currency-cash. lots of international scamming going on.

That is usually done at time of registration, on their end. They will need a bill of sale, possibly notarized. Easier going north than coming this way, believe me. Make sure your registration is totally removed from hull.

go to the source- us and can, gov'ts. make sure you are paid with good 'ole us currency-cash. lots of international scamming going on.

Also make sure there are not any other restrictions, environmental et al...

Now there is EXCESSIVE scamming going on with international sales, Canada really isn't bad but you might want to check with your bank on what transaction they would be comfortable with

Yes, they will have to pay General Sales Tax as well as any duties when they bring it into the country. If the boat is U.S. made there won't be any duties, but they will still have pay GST.