Hello, Jennifer! Welcome to planDisney. I'm glad you dropped by with your question before you head out to sea.
It sounds like your cruise is departing soon, so let's dive in. Yes, you are welcome to bring a case of water with you on the ship. There is no limit to the size of bottles. However, you must bring water in your carry-on luggage, and it needs to be able to fit through the security screening equipment with maximum dimensions of 22” high, 14” wide, and 9” deep. You will be responsible for carrying whatever water you bring with you onto the ship until your stateroom is available to enter, typically around 1:30 p.m. on the day you embark. For that purpose, it's wise to consider distributing water bottles amongst your carry-on luggage or in a rolling bag so you are comfortable and not dealing with heavy luggage while you wait.
If you'd rather not carry water during check-in at the port, you might consider purchasing a case of water on board. Crew members on board typically walk around at lunch time on embarkation day, asking guests if they are interested in purchasing a case of water to be delivered to their stateroom.
I like ice-cold water on and off the ship, so my preference is to pack two or three reusable, well-insulated water bottles for our cruise. You can visit the beverage station any time near the pool deck to fill up your water bottles. You'll be asked to use a clean cup to transfer the water into your personal cup. There are also water bottle filling stations along the promenade deck. My husband and I have a nightly tradition of going for a walk to fill our water, enjoy the ocean breeze, and stretch our legs before bed.
Long story short: you have options! And I'm certain you'll stay sufficiently hydrated to fuel the fun of your Disney Cruise. Before you leave home, please make sure you have the most up-to-date version of the
Disney Cruise Line Navigator app. The app will point your compass toward everything awesome happening during your sailing.
I'm wishing you a wonderful time! Bon Voyage!
Adrianna