On top of that, whether they use debit card or credit (better protection on your credit card), CALL your bank or credit card company & alert them that you are going on a cruise & what islands. This way they don't decline your card.
Many card companies (debit or credit) with all the fraud going on are declining cards left & right when they see "suspicious" activity.
I belong to Capital One. When I went on my cruise, I told them what islands I was going to be on during the time period. They emailed me back within hours & thanked me & marked that on my account.
It's just a piece of mind & a smart thing to do. After all, its your card & therefore your responsibility.