You walk down the docks and see a neglected boat. You stand by it and mess with the ropes for a few minutes, pretending the ship is yours. You offer the passerby the boat for 2000 coins, they happily accept. Who wouldn't?
You walk down the docks and see an apparently neglected boat. You stand by it and nervously pretend that the ship is yours. A rich man offers to buy the boat from you, but only if he can inspect the boat. You let him. As he enters the cabin, an uproar occurs. Oops, not so neglected. You make a run for it.