Lie-in King's link gives the best info:
http://www.cruisecritic.co.uk/articles.cfm?ID=225
For a specific company's policy, Google the name of the company followed by the word "smoking" e.g.
royal caribbean smoking
which gives this page (first, followed by others):
https://www.royalcaribbean.co.uk/frequently-asked-questions/
which gives this advice:
For the comfort and enjoyment of our guests, our ships are designated as non-smoking; however, we recognise that some of our guests smoke. Therefore, to provide an onboard environment that also satisfies smokers, we have designated certain public areas of the ship as ""smoking areas"".
Smoking in public areas is only permitted in designated smoking sections which vary from ship to ship. Generally, smoking is permitted outdoors on only one side of the ship. To assist in locating areas where smoking is permitted, you will find visible signage posted within all smoking areas and ashtrays that are provided for your use. The location of all smoking venues can also be found in the daily Cruise Compass; or you may contact Guest Services once on board.
For your safety, smoking is not permitted inside any stateroom or on any private balconies. Smoking is not permitted in any dining venue, food outlet, theatre, hallway or corridor; nor in Central Park, The Boardwalk® or The Jogging Track on Oasis Class ships; nor in the H2O Zone on Oasis and Freedom Class ships. A USD 250 cleaning fee will be applied to the SeaPass account if smoking has occurred inside staterooms or on private balconies. Royal Caribbean International kindly asks all guests to please observe the non-smoking areas and to refrain from smoking pipes or cigars in any of the public areas. These requests are made to provide a comfortable shipboard environment for everyone. Guests who violate this smoking policy may be subject to further action pursuant to the ""Consequences Section"" of our Guest Conduct Policy.
Pipe and cigar smoking is only permitted within the outer decks and the Cigar lounge. (If no Cigar lounge exists on a particular ship, there will be a designated outside area allowing pipe and cigar smoking).
A guest must be at least 18 years of age to purchase, possess or use tobacco products onboard. Cigarettes, cigars and pipe tobacco must always be properly disposed of and never thrown overboard.
At times, we may have to adjust our smoking policy to comply with the laws of a country we are sailing from. This information will be provided once you board.
Our new policy became effective for all sailings that departed on or after 1st January 2014
Please note, starting with all sailings which departed on or after 1st January 2014, our revised smoking policy is as below:
Cigarette, cigar, e-cigarette and pipe smoking is permitted in designated outdoor areas of the starboard side of all ships; with the exception of Oasis-class ships
that will allow smoking on the port side of the ships in the designated outside area.
To assist in locating areas where smoking is permitted, guests will find visible signage posted within all smoking areas and ashtrays that are provided for use. Outdoor areas near restricted areas, food venues, and kids play areas and pools will not allow smoking. On Oasis-class, smoking is not permitted in Central Park or the Boardwalk neighborhoods.
Casino Royale allows smoking and has a designated area for non-smoking guests. There will be visible signage indicating the non-smoking area in the casino. There are select cruises departing from China that will not have a non-smoking area in the casino.
Onboard all interior public spaces are smoke free*. Smoking is not permitted in any dining venue, theater, bar, lounge, hallway, elevator, and jogging track. Smoking is not permitted inside any stateroom or on any stateroom balcony. This applies to all stateroom categories onboard.
If a guest is in violation of this stateroom policy, a cleaning