I wonder if the ghosts can cross water? In many legends, ghosts (and vampires and other spookies) are unable to cross running water, so that one suggestion if you think you're being followed is to cross a bridge. Vampires notoriously have to cross a sea or ocean in a coffin filled with their grave earth. So I wonder if the ghosts can even follow them once they get on the ship? They should try it by crossing a bridge, and maybe destroying the bridge after them so the ghosts have to float across the water or stay behind.
Re: Chapter 15 - 698