I believe there are some precautions that can be taken, simple but effective. Most importantly it's not a guarantee anyone WILL be affected.
Wash your hands often, don't touch your eyes, nose and mouth. Too my understanding the virus thrives around the buffet areas. IE: People sneezing, touching the same serving utensils. The affected man sneezes in his hand, touches the serving utensil, you of course are the unfortunate one who is behind the man who just sneezed, you touch the serving spoon, touch your face.. WHAMO!
Look, I don't mean to downplay these things, but if you do get infected, the sink and the porcelan goddess becomes your best friend and then your all better in three days.
On my next journey, I'm really gonna try and eat at the regular sit down restaurants.
Most importantly, really. go on your cruise and don't worry about such things. Look, I'd be more worried about some loser boozer or some kiddies ruining my vacation.