After having been scammed twice by exceptionally cunning scammers (one of whom actually called me in person), I spend a lot of time identifying scammers, and trying to shut them down.
There are several things you can do, straight up, to find scammers, especially those selling items.
One, search for their email address using Google Search. It will often come up, inserted into other forums, selling the same scam item/s, with different physical addresses, or different seller names, or different phone numbers.
Two, do a Google Image search of the photos. 9 times out of 10, the photos come up on other sites, being sold by genuine people. The scammers also steal eBay photos and re-use them. Sometime they get clever and crop the photos.
But you can verify the item by requesting photos taken from specific angles and on a certain plain colour background. If the scammer can't produce those new photos, they haven't got the item they're selling.
Thirdly, make phone contact with the person and speak to them directly. Getting a phone number is a good method for ensuring traceability, if things go sour.
Speaking to someone usually establishes how genuine they are, using your shrewd judgement skills. Weigh up their circumstances and look for holes in their story - and be cautious about giving out bank details or other useful information until you've established a baseline character judgement about the person.
Remember that some people are actually genuine, but they're hopeless organisers, financially inept, and a hassle to deal with. It pays to be wary of these type of genuine buyers and sellers, as well.
KR Aviator, I'd suggest your boat purchaser falls into the latter category, and he's probably a bit of a rabbit, and an exercise in time wasting. Move onto to a genuine buyer with the money, who is properly organised.
FB is full of scammers and FB does nothing about them, they're good for driving FB sales income. You can find an obvious scammer on FB and report them and the message always comes back the same - "We have investigated and found no reason to suspend this account". Pigs bum they've investigated them, it's just a bot answering your request.
FB don't care one iota about scammers on their site, despite all the mealy-mouthed corporate bleatings about keeping the site free from scams.