Sounds like a guy who was on the forums
a year or two ago, claiming he'd bought a bought in NJ that was all ready to go to sea (except, the photos in the yard made it clear it wasn't) and all he wanted was some nice American chaps to help bring it to Bremuda or someplace for him, at their expense, because he wouldn't be allowed into the US because he was a pensioner and wouldn't be able to show financial proof that he could leave again...yadayada.
Forget escrow and look first to the basics. IF you buy a boat, unless it was pre-1972, you should be able to obtain a title (or state registration) or documentation
and you establish the title (regardless of the flag of the vessel) and pay the TITLE HOLDER to buy the boat. Along with buying
to protect you in the event the title is bad or their are claims and liens against the vessel.
The title holder has the title with him, overseas? Find, let him hire a US representative, which could be a broker, bank (someone's got to accept the money for him), or lawyer. Make the exchange in person here. If the boat is at a yard, someone from the yard will be able to exchange paperwork for a reasonable fee.
Meanwhile, you should be able to get a clear photocopy of both sides of the title and conduct a title search on the vessel.
It would probably help to know more--like how the vessel is flagged and titled, and the nationality of the owner.