Smoking is prohibited on board most areas of RCI ships. However, to provide an onboard environment that also satisfies smokers, they have special designated smoking areas in many their lounges and on all open-air decks.
Most cruise ships have a policy at the moment of having one side either port or starboard, our our ship it was starboard, but you have to ask for an ashtray they are not always out on the tables if you arrive early on. Our cruise line allows you to smoke in the staterooms as they are well ventilated but again you need to ask for an ashtray.