I've meant to post this for some time... For those of you with of you traveling with children. My 14 yr old son is from my first marriage , and therfore does not share my last name. On our last cruise, we also brought his friend.
The following documents made my life much easier...For my son, I had a copy of the court documents that listed me as his custodial parent. For his friend, I had a notarized letter from his parents. And copies of their birth certificates. I put all these papers, our cruise documents and color copies of our passports in a 3-ring binder, each page in a plastic sleeve.( I also printed a layout of the ship, but that's just plain obsessive)
It made check in much easier and I knew that I was going to be allowed on board no matter what. Before you go, check the cruise lines requirements for your children, they're extensive especially if both parents aren't going!