Well, we don't smoke and do generally book with cruiselines who limit it, at least. We used to go on Carnival and enjoyed it very much.
However, we usually book with Holland America. They do allow some smoking, and are pretty liberal about it on verandahs and in cabins, so we book an outside to avoid it.
Actually most people on Holland America are older, so I imagine most the smokers who booked with them have passed away from smoking related illnesses.
Have a nice cruise. I am sure you will be able to avoid the smoke if you try.