Being trapped on a boat full of strangers for a week at a time can be a difficult proposition. Themed cruises are a good way to ensure that you're surrounded by like-minded people. Or, at least, someone you can talk to about a shared interest. Sometimes, though, themed cruises can get a little bit out there. The cruises on this list are some of the strangest. Whether you're into zombies, nudism, or you're a nudist zombie, there's something here to interest you.
If you're really, really into wearing spandex and dancing, the Zumba Cruise might be up your alley. Fitness cruises are actually on the rise, as more and more health conscious people come to see "sweating on a boat" as a worthy vacation goal. If you're not part of the CrossFit set, this might be a happy medium.