Re: Tracing history by registration number??
first advice: don't deal with a dealer who "isn't forthcoming." If he doesn't have a clear title in his hands--and you see it--walk away. In fact in some states it's illegal for a dealer to sell a vehicle if he doesn't have the title; maybe boats are the same? And is there a trailer involved?
Is the dealer in MN? When you talk to MN DNR mention this guy selling a boat with no title and see what they say.
Every state is different, but in Virginia, AFAIK, you can't just call up and ask but you can get that info if you are in the process of dealing with a boat abandoned on your property or left in your storage/shop with unpaid storage/repair bills. You can't buy one and then say it's abandoned, etc. However, in your case, IF this dealer were honest, he has the means to clear the title. Put it all on him; do nothing and spend nothing yourself.
bottom line is that if your seller, a dealer, won't tell you what he's selling, you ain't buying.