On most any cruise ship, passengers get frustrated by “chair hogs,” or people who try to claim a pool deck lounge chair for an extended period of time by leaving their belongings on it and then disappearing. Cruise lines discourage this behavior but it persists, especially on Carnival and Royal Caribbean cruise ships.

Over 90 people contracted gastrointestinal illnesses from an unknown source on a week-long Royal Caribbean cruise, the CDC said Wednesday. Both passengers and crew aboard the Radiance of the Seas have experienced vomiting and diarrhea.