1. Another aspect I've seen more than a handful of times, is where the owner is growing in to his/her golden years. So far as the family
are concerned, Dad say, isn't able to manage the boat and so should get rid of it.
But owner doesn't really intend to sell the boat and give up the dream, but that family
are pressuring. So owner lists boat at a price he/she knows it will never sell at. (Well if an idiot does come along, and is willing to pay way over the top, why not?)
But the listing shuts family up, at least for a few months, and keeps the boat.
2. Alternatively the owner has died. The family just see a liability, mooring fees
costs. Family members just want those liabilities to go away and so the sooner boat sold
When no one in the family has any interest or knowledge, buyers can find very very good bargains.
3. Or even more extreme, but not uncommon, owner dies without a will, there's no family claim, and so the marina is left with the problem of no one paying the mooring fees
4. The owner can't or wont pay the mooring fees. Eventually the slip owner/marina takes action and take possession of the boat in lieu.
5. Boat has been an insurance
write off and is being sold on behalf of the insurance company. Some great bargains are to had by the discerning and knowledgeable buyer this way.
In scenarios where the seller is a third party and their interest is limited, then so long as they cover their costs they're often satisfied to do the deal. Typically they don't want a problem boat because most boats have ongoing costs. Sure they know that the boat is worth more, but they don't benefit from this. Laws in most locales expect the 'profit' should go to the owner or his/her estate.