I think the way to really piss someone off who is a smoker is to drop in a non-smoking policy
after they have arrived (and after you have banked their cash), or even to overly restrict them on times.
An entirely non-smoking boat is fine with me - your boat, your decision, it just comes down to what your market wants. Personally I would start by making the policy (publically) as on
deck and downwind (or whatever that works on your boat)and then count those who do smoke / whether it has an impact on your bookings - after that can decide whether to go for the full ban.
Although as a Smoker who is firmly in the camp of "you can take my ciggarette when you can prise it from my cold dead hands" - nonetheless I am actually happy about certain places being non-smoking....as long as "civilisation" is within puffing reach!, so for me on
deck somewhere (Force 10 or above is ok with me!) is a requirement......but I appreciate that I am not required onboard
your boat.
What you want to avoid is folk having a sneaky fag somewhere that causes a problem (for boat or for others).