P&O allow it because I have just called and asked them. You can smoke in your cabin, on balconies, in desgnated areas inside and outside- hope that helps, also Princess, Thomson, and many more......Silversea...etc...etc.
Do you realise that when you smoke in your cabin the smell and the smoke permeates into the cabins each side of you and can be extremely unpleasant to the other passengers plus the staff that service your cabin are being subjected to obnoxious cigarette residue. If you really must smoke be aware of the majority and do it well away from others......Nei.
Neil you haven't answered the question!!!