Star Wars: The Last Jedi rewards careful viewers, and one of the more interesting and subtle moments was spotting Luke Skywalker's iconic X-Wing sunken in the shores off his island home in Ahch-To. I was thinking about why we saw this and, aside from explaining how Luke got there in the first place, it functions as a red herring to preserve the twist of Luke's Force projection in the finale. After all, without a working ship there's no way he can leave the planet (and we already know the X-Wing can survive immersion in water from Empire).