Congratulations on your upcoming wedding! I too am getting married in December and my fiance and I will both be 20. We are going on a cruise for our honeymoon too, and i was told to bring the marriage certificate. I wastold to bring proof of marriage, so i just planning on bringing the uncertified original. So that should be fine. Let me know if a copy of the marriage certificate will do, and if you have any other suggestions when you get back. Good Luck :)