It seems each month there is a news report about a crewmember assaulting a passenger while on a cruise. Vacationers take cruises to relax and have fun. Cruise lines spend millions of dollars portraying their ships as the model of safety and security. This combination causes people to let their guard down and makes them a target for predators. Recently cruise lines such as Royal Caribbean, Disney, Carnival and NCL started releasing better statistics of crime committed on their ships. Statics coming from these cruise lines are quite disturbing and showcases the fact cruise ships are not safe places they appear.
The best advice is to not let your guard down and position yourself to not become the target. This is accomplished by traveling in groups, not over indulging in alcohol, staying away from unlit secluded sections of the ship and not flashing money and expensive jewelry.