Singapore’s attempts to resuscitate its fledging cruise sector have been dealt a blow after a passenger aboard a "cruise to nowhere" tested positive for Covid-19.

The incident aboard Royal Caribbean International’s 169,000-dwt Quantum of the Seas (built 2014) forced about 2,000 guests to be quarantined in their cabins.

“A guest was feeling unwell and tested positive for Covid-19 ... we are asking all guests to remain in their staterooms to prevent the spread of illness,” the ship’s captain is reported to have told passengers over the ship’s tannoy.

“We kindly ask all guests with urgent medical or health situations like diabetes, heart disease etc to contact guest services,” he added.

Singapore has been piloting the "cruise to nowhere" concept, which is open only to residents, makes no stops and sails in waters just off the island.

Royal Caribbean confirmed in a statement that all guests and crew who had close contact with the infected passenger have subsequently tested negative for the virus.

"Emergency response plans have been activated according to guidelines including immediate isolation of close contacts, contact tracing and deep cleaning of the ship," Annie Chang, director of the cruise segment at Singapore Tourism Board told Reuters.

Restart of cruise operations

Royal Caribbean's "cruises to nowhere" from Singapore began last week, marking the cruise line’s first sailing since it halted its global operations in March due to the pandemic.

Genting Cruise Lines and Royal Caribbean International originally unveiled plans to restart cruise operations in Singapore in early October.

Both cruise operators went to great lengths to minimise the risk of any coronavirus outbreaks on board their ships, including mandatory testing before boarding.

Initially, the "cruises to nowhere" were restricted to between two and four nights, with the passenger capacity capped at 50% for at least the first three months.

DNV GL was tasked with creating a cruise-compliance audit and certification programme for cruise lines that wanted to restart operations out of Singapore.

The classification society reportedly won a tender for the work worth SGD 145,000 ($106,000) from the Singapore Tourism Board, according to local media.

The initial cruises where well subscribed due to pent-up demand from Singaporeans who have been living under Covid-19 restrictions since April.

While Singapore was initially hit hard by the pandemic, daily new infection numbers have dropped to single digits, with most new cases involving foreign arrivals under quarantine.