Cruising is a learning experience. As with any vacation that is being taken, it is always advisable you inform your banking institution as so a situation such as your doesn't put a damper on your trip. We have two bank accounts (at different banks) but always used one of them for our cruises and never had an issue. On one cruise last year, we decided to use the other bank for a cruise and even though we did inform them we would be traveling, they still locked our account while we were in the middle of the Gulf of Mexico due to the incremental charges the cruiseline applies during the cruise.  The ship allowed us to call our bank to try to straighten out the issue but the bank would do nothing over the phone. The crew aboard the Brilliance of the Seas were very accommodating and also explained that this has happened to other passengers in the past with the bank we were using. We had no choice at this point but to use the other banks card but could only withdraw from the onboard ATM (they wouldn't allow us to use a different card) but we were able to pay in cash. So as you see, even after 9 cruises (at that point), there could still be issues. My advice is to make sure  you advise your bank in person of your travel plans and they put a notation on your account as so not to "flag" your account for repetitive charges from the same vendor. Don't let this shed a bad light on cruising, like I said, cruising is a learning experience.