Many passengers of both cruise lines believe that the the smoking and non-smoking casinos should be flipped. They think Royal Caribbean and Carnival should follow the Virgin Voyages model and segregate the smokers into a space so non-smokers can avoid being exposed to secondhand smoke.

The Royal Caribbean Cruises (RCL) stock price is firing on all cylinders and outperforming its closest rivals like Carnival and Norwegian. It has risen in the last three consecutive months, and is sitting at a record high of $193.

Celebrity Cruises does not allow smoking in its casinos. That's a pretty extreme choice given that only one casino on the Las Vegas Strip, MGM Resorts International's Park MGM, fully outlaws smoking in the casino.

Related: Carnival Cruise Line shares a strong warning Cordoning off the smokers into a small space also protects cruise ship workers from secondhand smoke. Aside from roving waitstaff, the Virgin Voyages smoking casino is not staffed.