Ahoy, Patricia!
Thanks for stopping by the Disney Parks Moms Panel with your question!
One of the perks of sailing with Disney Cruise Line is that
soft drinks are complimentary 24 hours a day at the self-service Beverage Station on the pool deck of every ship in the fleet. You'll find a variety of Coca-Cola brand soft drinks, including Coca-Cola, Diet Coke, Sprite, Minute Maid Lemonade, Seagram's Ginger Ale and Fuze Iced Tea (offerings always subject to change). The drink stations have coffee and hot cocoa available as well. Paper cups are provided for guests, but I always pack a travel mug or purchase one in the onboard gift shop to fill up with my favorite soft drink. While I haven't seen seltzer water as an offering at the drink stations, I'm sure you could request it at one of the bars onboard (possibly at an additional charge).
If you'd like to bring your own favorite brand of seltzer onboard, you're more than welcome to pack it in your carry-on bag!
I hope this helps with your planning. Have a magical day! - Diane W.