Absolutely;we checked a case of water on two different ships in Feb and they werre delivered to our room with our suitcases.You can also bring with you as you board if you so desire.
FYI -- The water that you get out of the tap in the bathroom is as pure as any bottled water that you can buy. Just bring one bottle and keep filling it up. All the cabins also have real refrigerators to keep it cold.
Jim.