Earlier quoted context omitted.
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.
I think this is bad idea. Maybe have a special room for smoking? > Smokers don't have to smoke, they merely choose to do so. Some people are legitimately addicted. I know for a fact that I am not (I can go for a month without smoking and I won't go crazy) but removing smoking or nicotine will be a major quality of life downgrade for me.
And some people aren't fit to serve on submarines.