To be honest I'm not bothered about whether it's Coke or Pepsi. I quite enjoy both so I would definitely err on the side of the latter with regards to your question. In the UK we use Coke as a generic term for all the cola's but hopefully they have Diet Pepsi or Pepsi Max on Carnival? I've had the Barcadi spiced rum before and it wasn't very nice in my opinion but it is what it is. Just happy to be cruising abroad again!