Welcome mronvacay. You'll find a lot of answers at the wiki summary of this thread.

A couple of decent credit and ATM cards should get you through the trip, but bring some USD cash, too, just in case. Be warned that if Citi interprets your charges as being made outside the USA, they'll tack on a 3% charge regardless of currency. So if the cruise company bills things in USD through their Miami office, you'll be fine. But if they bill things through an office overseas, even if the charges are in USD you'll pay 3% to Citi for the privilege of using their card.

I'd definitely recommend getting something else. Schwab is the current favorite in this forum.