So expect to put on weight, and work it off in the gym. And for those on a seafood diet, you can eat all the food you see. However, make arrangements in advance. Tip them overboard or poison them. Alternatively, speak with the onboard maitre d' who will make every effort to seat you with more compatible dining companions.
Many dining rooms are now totally smoke-free, and at least one ship bars smoking altogether.
Fortunately, there are no alcohol-free ships. Yes, cruise Lines will make a fuss of you. Most will even treat you to a complimentary cake and champagne. In one evening, the SeaView editor sat through 12 renderings of Happy Birthday, with blazing cakes, which pretty much answers the question. You can even arrange for a special private party.