Sold a boat. Now what with DNR?

So I sold a boat the other day. New thing for me. For the trailer I did the seller’s notice of sale online. It mentions that it should be done within ten days of the sale. No problem.

I found nothing regarding the boat itself. So I called the DMV and they said that part is thru the MN DNR, not them. They gave me a 1-800 number that puts me on hold all day. Do I have to notify the DNR that I sold a boat?

Thanks

Make sure to get the trailer title changed over. Didnt think much of doing that on my sold boat and ended up with a parking ticket about a year later. With lifetime trailer tags there isnt much incentive for new owners to change the title.