Passengers on the British cruise liner the Aurora are sailing towards Gibraltar, after being refused entry into Greece.
The Aurora set sail from Southampton
About 400 holidaymakers on the P&O ship were affected by a highly contagious stomach bug, although all but 30 are now thought to have recovered.
Earlier on Friday, Greek doctors boarded the £200m superliner after authorities refused to let passengers and crew disembark at the port of Piraeus, near Athens.
A P&O spokeswoman told BBC News Online that somebody had died during the cruise, but that it was entirely unrelated to the outbreak.
The disease is believed to be a Norwalk-like virus, which can cause diarrhoea and vomiting for up to two days and strikes where there is inadequate sanitation - mostly in hospitals and schools or on cruise ships.
P&O said the ship, which is based in Southampton, will continue its cruise as planned, with 1,800 passengers and 600 crew on board.
The buffet, thought to be
the food outlet most at risk from person-to-person transmission of the virus, has been closed.
The spokeswoman said spirits on board remained high and that nobody had been seriously ill with the bug.
'Confined to cabins'
But passenger Sheila Haigh told BBC News Online she was worried about catching the bug, because she suffers from a rare immune system condition.
"It isn't contained - you don't know what's going to happen.
"They are sterilising cabins, people with masks are cleaning everywhere - the crew are doing everything they can."
"Passengers are washing their hands but I suspect people are not quite as good with that as they want to be. A lot of people are confined to their cabins.
Fellow passenger Sheila Elton said it was the second time in a year she had been on a P&O cruise that had suffered a suspected Norwalk virus outbreak.
"Yet again it is like a sword hanging over you, are you going to be the next one to succumb. We are taking all the precautions and staying mainly in our cabin.
"Sometimes you would hardly know there is anybody about - you don't see a soul which is most unusual. The atmosphere is a combination of gloom and worry."
David Dingle, managing director of P&O Cruises, said: "We are doing everything to ensure that our passengers are having an enjoyable time. The mood on board the ship is positive."
He said the decision by Greek authorities to not allow the ship's passengers to enter the country had been unprecedented, given that the people who had been contagious would have been held on board.
The Gilbraltar authorities will decide over the weekend whether or not to allow the ship to dock in its port before it arrives on Monday.
A Government of Gibraltar spokesman said: "Reports being received from the ship appear to indicate that all but 30 of the affected passengers have now recovered".
Earlier a P&O spokeswoman said comprehensive procedures were in place to deal with what was being treated as a case of the common Norwalk virus.
The company believes the disease was brought on board by a passenger at Southampton, where the cruise began on 20 October.
During a stop in the Croatian city of Dubrovnik on
Wednesday, health inspector Ivo Miloglav ordered the sick passengers to remain in their cabins.
They had not been permitted to disembark during
the ship's previous stop, in Venice, Italy, he added.
The 76,000-tonne ship has been struck by bad luck, with its maiden voyage cancelled when it broke down one day into a two-week cruise.
And even at its christening, by the Princess Royal, the traditional bottle of champagne dropped into Southampton Docks instead of smashing against the ship when a bottle-release mechanism failed.
My 84 year old mother-in-law is on board, accompanied by her carer. All her life she has dreamed of going on a luxury cruise, as she once cruised the med with her mother when she was a small child. Life took her in other directions and only now has she been able to realise her dream - a dream which has possibly turned into a nightmare for her. At her age catching this bug could have serious consequences. My husband, Ian, her son, and I are obviously worried to death.
Christine Couper, UK
I have been on many P&O Cruises in the past years and this comes as a shock. However, please let it be known that this is a shock case of it and most cruises and very enjoyable. These ships are well maintained and as a previous passenger can believe that the staff are doing everything they can to help every passenger and that most people on board the ship will still be having an enjoyable holiday.
Daniel Holmes, West Yorkshire
Oh dear! I am disabled and booked a holiday aboard Aurora for next April earlier this week. I do hope they completely eradicate such viruses on board by then...
My mum and dad are trying to have a holiday to help my mum recuperate from Guillain-Barré Syndrome, which she contracted on her last holiday. I spoke to them on the phone this morning and so far they have been lucky, neither have contracted the bug. However mum is very vulnerable after being ill last year, so they are taking extra precautions e.g.. not using the public toilets etc
Stefany Anne Brown, UK
Not on Aurora, but came off Oceana 24/10/2003. The ship tried their very best to look after us including issuing disinfected hand wipes as we went into to buffet. However, there were passengers who felt this was beneath them and waved them aside. With this sort of arrogance how can ships protect their passengers? People should think of others and not show off.
Lyndsay Piper, England
My wife and I took a cruise on the Aurora 18 months ago when it was new. It had constant problems with the waste plumbing. Our toilet frequently blocked, the whole corridor had no flush for 2 days. The staff mopped up the overspill with bath towels - I have no idea if these were re-circulated. A number of areas smelt of sewerage.
Paul Evans, England