A gastrointestinal illness has broken out this week on the Radiance of the Seas cruise ship, according to the US Centers for Disease Control and Prevention.

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.