The Celebrity Mercury cruise ship is reported to return to port a day early from its scheduled date and its next sail will be delayed by two days, addressing an outbreak of gastrointestinal illness that reportedly sickened 350 passengers.

The outbreak is discovered to be the third consecutive outbreak on the ship in a month.

The delay is introduced so that Mercury can undergo an enhanced cleaning because of the norovirus outbreak, an illness marked by diarrhea and vomiting.

"The CDC and the cruise line corporate staff have not yet determined why the controls that they were following have not been effective", revealed CDC spokesman Ricardo Beato.

The Centers for Disease Control and Prevention had initiated with a no-sail recommendation for the ship on Monday to launch an investigation into the recurring outbreaks.

Martinez has addressed passengers saying that those who want to proceed with the shortened voyage will receive a pro-rated refund for the two lost days in the form of an onboard credit as well as a future cruise certificate in the amount of 25% of the amount they paid for the voyage.

The ship is slated to board on Sunday.