All I know is that in Wisconsin, and most other states as far as I am aware. If your boat is documented you still must buy a state registration and display the sticker on the stern. No need to post numbers on the bow.
I very recently started a thread on this very subject. Search "Refresh my memory, why do I need to document my boat" It should still be active, you won't have to look very far down the list.
I received lots of good answers, you will also.
pete