You may bring on your own soda and bottled water. I also recommend bringing your own sports style water bottle to fill with ice and tap water (which is fine). Lemonade, iced tea and punch are usually available after the noon hour and OJ and apple juice (breakfast time) at the buffet.
Do they charge for juices also? Or are they included on your soda card? I have a teenager coming with us on our next cruise and she doesn't like carbonated drinks. Should we plan on bringing a lot of juice and water with us, is this included in the soda card, or is juice available all day (I assume that water is available at all hours)? Thanks!