Yes, Faster is correct. I just imported a boat from Vancouver to the U.S.
It was surprisingly easy, especially since Faster drove me from the train station to the boat. Maybe he will do the same for you.
I will post a quick reply now and more later...
1) Because of NAFTA, as long as the boat is of U.S. or Canadian origin, there are no taxes or duties for importing the boat.
2) You do not need a customs broker, if you are bringing the boat across yourself.
3) The whole process cost me about an hour and around $30.
4) I was pretty anxious about it, but it was easy.
5) The most difficult part of the whole transaction was the conversion of funds from U.S. to Canada. It seems that everyone wants to take 2%, and they aren't exactly upfront about this. Part of the problem was that I was transferring money from my credit union, instead of a bank.
I used a Canadian escrow company and they converted funds without the surcharge. That more than covered their escrow fees.
I will dig up the documents I had, and repost later today.