It was one of the largest norovirus outbreaks on a cruise ship in 20 years.
The Royal Caribbean's Explorer of the Seas returned to New Jersey on Wednesday after cutting its 10-day Caribbean voyage short.
The US Centres for Disease Control and Prevention has said 630 passengers and 54 crewmembers were sickened. The ship was carrying 3,050 passengers.
The CDC has not yet pinpointed a source for the norovirus. It can be picked up from an infected person, from contaminated food or water, or by touching contaminated surfaces.