It depends on where you are cruising to. If you are taking an Alaskan cruise and will make a stop in Canada or take an excursion that goes into Canada, you do not need a passport until 2008, BUT you will need a certified birth certificate (original). The only catch is, if you get sick or hurt while across the boarder, they can not fly you out. You can only drive out or take the cruise ship out. I had my kids go ahead and get their passports for our trip this week-end, just to be safe and it makes it a lot easier. Be aware, it's taking a lot longer to get a passport these days. It took my daughter 12 weeks (just got it 2 days ago) and that was after I had called three times last week asking them to push it thru.