A Royal Caribbean "cruise-to-nowhere" from Singapore began disembarking its nearly 1,700 passengers who were confined to their cabins for more than 16 hours on Wednesday after a Covid-19 case was detected onboard, forcing the ship back to port.

All passengers aboard the Quantum of the Seas had cleared a mandatory polymerase chain reaction (PCR) test for the virus up to three days before the four-day cruise began on Monday.