Buying from a private seller

Hi guys, I made a search on the forum but didn't find what i was looking for.

I'm expending my search for a used boat. I was looking initially to buy local (New England), but the selection and prices are not there. So now i'm looking further away, and if I make a purchase, I will probably need to get it shipped.

When you buy from a private, how do you do the deal? You fly in and bring 20K$ in cash and hope for the best? Send a cashier's check, and wait the check to clear a week later? Most sellers I've contacted don't want to do wire transfers, and i'm not to sure it's safe with paypal.

Please tell me what you think is the safest way of doing such a transaction. When do you transfer titles, etc..

Thanks!!