Weird things happen while out at sea, and one of those weird things involves people going missing. Around 165 people reportedly went missing while on a cruise from 1995 to 2011. Some people think that number is possibly higher. And we're not talking about passengers that fall overboard — although that is one likely explanation for those numbers. We're talking about people who simply disappeared without a trace and were never seen again.
Apart from going overboard, other likely explanations include people being kidnapped and taking their own lives while on a cruise. However, we wouldn't completely rule out the possibility of a passenger throwing another person overboard.