They allow 2 bottles of wine or champagne per cabin, however, my travelling companions and I have always carried on 2 EACH and they've never said a word. This was out of Port Canaveral so I don't know if they enforce this differently elsewhere but I imagine it's a cruise line thing, not a port by port issue. I've never tried to carry on a whole case of water but I do bring a water bottle full of heavy whipping cream for my coffee every cruise and again....no issues.