Earlier quoted context omitted.
But subs get deployed for 6 months at a time. Unless they banned smokers from getting into subs??
You don't have to ban smokers to ban smoking on a sub. Smokers don't have to smoke, they merely choose to do so.
Incidentally, that's precisely what helped me quit (a long time ago): I realized I was a slave to the cigarette and the only way to be free again was to stop it altogether. It was one of the hardest thing I ever had to do. I stayed in bed for four days trying to think about something else and sleeping it through. And then it wasn't over for a couple of weeks.