Like most long distance advice.
Do your research on the buyer, especially if it is a broker, they will have a web foot print.
Second, talk to your bank and have a special account set up to receive a wire transfer. After the transfer is received, the account disappears.
No money orders, no checks. It will prob cost you 30-50 for the account but I would consider it worth the insurance.
Make sure the BOS clearly states the purchase is sight unseen, IF he buys the boat sight unseen, which is crazy IMO. You don't want to give him any chance of pulling the money back once the boat leaves your location.
Having a broker involved in a purchase deal, especially an "average" "lower cost" boat does throw some red flags but not unheard of.
1991 MariStar 240sc, 454, tower, WetSounds, Krypt and Rockford Fosgate