http://www.cruisecritic.com/articles.cfm?ID=61 Norovirus doesn't usually occur on ships, it occurs everywhere it is just reported more and quicker if it is on a ship. There are so many cruises each year, most of which do not have noro outbreaks. You only hear about it when it happens, they don't mention all of the many other cruises where people do not get norovirus. And if you look into the figures it is classed as an outbreak if as low as 2% of passengers and crew are infected, if you think about the number of people on some of the cruises, 2% is not that many. Your odds or contracting it are low if you keep up with the usual hand hygiene as once it is onboard the ship puts in all of these measures to eliminate it and stop the spread. If a ship sinks, you could die, but I don't think many people have ever died from norovirus! You may not even v* if you do get it.
.