Might get a little hard to balance ship inventory on some cruises. FWIW, I smoked for 2 decades and quit 2+ years ago and was recently on a Holland America Alaska cruise and barely noticed any smokers. Once or twice past the piano bar I saw a few wisps of smoke but on a ship the staff said was completely full it seemed only a small percentage were smokers, though every sailing would no doubt have a different composition of course.

Here's the Cunard policy:

http://www.cunard.com/FAQ/faq.asp?Ca...=&ArticleID=13

For the comfort and convenience of all guests, elevators, and some restaurants and public rooms have been designated as non-smoking. Many public rooms offer both smoking and non-smoking areas. Guests who enjoy pipes or cigars are accommodated in Churchill's Cigar Lounge onboard QM2, and in the Chart Room, Golden Lion Pub, Crystal Bar and open decks onboard QE2. We ask that guests refrain from smoking pipes or cigars in other enclosed public areas of the ship. Aboard QM2, each public room and bar have designated smoking sections and all restaurants are non-smoking. Aboard QE2, each restaurant provides a small section designated to cigarette smoking with the exception of the Princess Grill, which is non-smoking. Each public room and bar have designated smoking sections. The elevators, theatres and library are designated as non-smoking.