PORT CANAVERAL -- Nearly 230 people aboard a cruise ship fell ill with a gastrointestinal illness during a weeklong Caribbean voyage, the company said Saturday.

The illness, believed to be a norovirus brought onto the Mariner of the Seas by a passenger, struck 221 of the ship's 3,660 passengers and six of its 1,202 crew members, said Royal Caribbean spokesman Michael Sheehan.

Sick passengers started complaining of vomiting and diarrhea Wednesday and were treated with over-the-counter medication, he said.

Most would be recovered by the time the ship docked Sunday morning in Port Canaveral as originally scheduled, Sheehan said.