Yep, the Moose is correct,,,steamers are the way to go, or you can do as the lovely Mrs. Jones (Vita) does. She just brings along one of those spray cans of wrinkle release. They seem to work just fine too. (except on my face)
You're going to love Eastern Caribbean. I've been all over the world, and still think that St. Thomas, St John is one of the most beautiful beaches in the world. St. Martin is very unique too.
Have a great cruise,