Royal Caribbean's Oasis of the Seas is considered one of the largest cruise ships in the world.
On Sunday, more than 5,000 guests and crew members were on the Caribbean cruise, which was scheduled for seven days.
The Castros, who were part of a group from Margaritaville, said the fun was cut short on Tuesday.
That's when many passengers reportedly started feeling symptoms that included nausea, vomiting and diarrhea as the ship approached Jamaica.
Royal Caribbean said more than 400 passengers and crew members were hit with an outbreak of norovirus.
Officials said the Centers for Disease Control and Prevention is investigating. They said norovirus is the leading cause of foodborne illness in the U.S., with most instances of norovirus occurring in public places like restaurants.
Passengers said crews sanitized common areas as ship officials urged passengers to wash their hands and stay in their rooms.
The ship returned a day earlier than planned, and the cruise line said passengers are getting a full refund.