Cannot answer the question specifically BUT there is no reason why you cannot buy your own bottles of water from the shops and supermarkets in and around ports. Usually MUCH cheaper than any "package" which is just a way of frightening you into paying money now ! Bottled water can be found everywhere you go especially in Europe (which I assume is where you might be going?) I always do this and bottled water taken on board, has never been an issue with any cruise line so far.
This is an American cruise line and Americans are VERY frightened of eating and drinking anything that they do not recognise as being from the USA. They will buy Coke but not local bottled water even though in the whole of Europe, this is perfectly safe. Hence the packages are really pandering to their fears. Do not join them !! If you are leaving from Southampton you could do as I do. Buy two 5litre bottles from the supermarket. Put luggage labels (securley) same as the ones for your luggage with the cabin numbers on etc. Then hand them over to the porters with the rest of your luggage to be taken to the cabin. I have been asked once why I have the water ! I replied that it was low mineral for my kidneys. (True by the way) Hope this helps.
Thank you very much for your helpful answer.
HIYA there asking about independant of the seas then put subject island cruises and island is not ameerican cruise line.