I'm also a Coke guy living in Atlanta much of my adult life. Two options although neither not great but when on Carnival, you do whatever you can do ... you can bring a limited supply of canned sodas on board (I have not checked the rules yet for our upcoming 08/06 cruise but plan to shortly). The other option is to use Pepsi Zero (not Diet Pepsi!). I know it's diet but it is actually not far off Coke - especially when used as a mixer. Hope that helps.