Air exchange and filtration systems on jet airplanes are extremely good. The air exchange on a plane happens very quickly. Cruise ships not so much. They're

Air exchange and filtration systems on jet airplanes are extremely good. The air exchange on a plane happens very quickly. Cruise ships not so much. They're fairly basic systems like a home or office would have. They aren't continually recycling, filtering and exchanging the air like pressurized plane does. They cycle on and off as temperature demands and they don't move the required volume of air. Ever notice how farts on planes dissipate faster than ones in a room?