SINGAPORE - For the second day in a row, British couple Elaine and John Spencer have whiled away their time watching movies in bed and having meals delivered to their room.

This may sound like a dream holiday to some, but with no windows and no option to leave for the next 12 days, cabin fever is beginning to set in.

The couple, who embarked on a cruise in Singapore on Jan 6, are among the 3,700 passengers of the Diamond Princess now under quarantine in the waters off Yokohama, Japan.

"We're keeping ourselves busy as much as possible, but you start to lose track of time with no daylight," Mrs Spencer told The Straits Times in a phone interview from their cabin on Thursday (Feb 6).

Ten aboard the ship were confirmed to have the coronavirus on Thursday, a day after 10 others tested positive and were moved to medical facilities onshore.

The ship, carrying 2,666 guests and 1,045 crew members, had arrived at its final destination of Yokohama a day early on Monday. This came after an 80-year-old man tested positive for the virus after disembarking in Hong Kong on Jan 25.

Guests have been confined to their rooms since Wednesday, the start of the 14-day quarantine, as Japanese health officials race to screen passengers and contain the coronavirus, which originated in the Chinese city of Wuhan.

Princess Cruises, which said about half the ship's passengers are from Japan, did not respond to queries on whether any Singaporeans were on board.

The infected passengers are from China, Japan, Canada, Australia, New Zealand, the United States, Taiwan and the Philippines.

The Spencers, who boarded the vessel at Singapore's Marina Bay Cruise Centre for a 29-night cruise of South-east Asia and Japan, watched the spread of the deadly virus unfold on their television in the last four weeks.

The ship had called at ports in Vietnam, Hong Kong, Taiwan and Japan.

"The last week or so, a lot more passengers who boarded the ship were wearing masks.

"Other than that, I didn't notice any problems," said Mrs Spencer, 54.

But the day before they were scheduled to disembark, they were told a former passenger had been infected with the coronavirus, and their temperatures had to be taken.

"We were still mixing about and going to the lounge for meals. Then it trickled through that there were confirmed cases and we had to stay on board," she said.

The couple have been screened by Japanese officials and have yet to show any symptoms of the virus.

Despite learning of the new cases, they are not worried that they could have contracted the virus.

"We are very good at washing our hands," said Mrs Spencer, a health and social care trainer.

Since Wednesday morning, all guests have been confined to their rooms for the rest of the quarantine period. Meals are delivered to each room three times a day by staff wearing masks.

Some passengers have taken to social media to comment on the food and the need for medical supplies for those on prescription medication.

Facebook user David Abel, who gives daily livestream updates from his cabin, said in a video on Wednesday: "The meals have completely changed. We are definitely no longer on a luxury cruise... I'm so grateful to the ship for taking care of us, it's just a contrast to the first two weeks."

A passenger who declined to be named told The Straits Times the same day: "I think we are a bit low on food because it's some weird combination they have sent for lunch - ham and cheese bun with a few crisps and a bit of pasta."

Mrs Spencer said that while food service can take up to three hours to complete, "we recognise that they have a huge job to do and they're doing their best".

"My husband's a vegetarian and they managed to accommodate that. This morning, we got menus to choose what we want - the only thing I'd really like is some coffee," she said.

Those in need of medication and other provisions can also make requests.

"We're all fed and watered. It's just boredom at this point. We're running out of films to watch, though there are quite a few TV channels," she added.

Among them is a feed from the bridge camera - their only view of the outside world.

For exercise, Mr Spencer, 55, jogs on the spot daily for an hour.

"We were told today that we would be allowed to go on deck at some point with masks in small groups. I hope to be able to get some fresh air," Mrs Spencer said.

While being confined to a room just large enough for a king-size bed, desk and small en suite bathroom is daunting, the couple are taking it in their stride.

"We've been married a long time, so I think we'll be okay, we won't strangle each other," she quipped. The couple are celebrating their 20th wedding anniversary this year.

"It's my grand-daughter's birthday today. Eight years ago, when she was born, we were on a cruise as well. I don't think we'll be doing another one for a while," she added.

"We're hardy travellers. I'm more disappointed about missing out on the last three weeks of our holiday when we were supposed to go to Thailand and Dubai."

While their first trip to Asia did not work out as they had hoped, it will not be their last.

"We were in Singapore for three days and it was lovely. I love the heat and the gardens. I'm sure we'll be back," Mrs Spencer said.

Additional reporting by Walter Sim