probably not, no immigration on the island. considering a passport is a legal doc. But, what a great idea, kind of like what they have in Epcot, the kids loved getting stamps from all the countries, what if they had booths at the docs for all the ports where the kids could do the same thing! how cool would that be.
We have used our passports on three Disney Cruises and do not have stamps from any port.
As for Castaway Cay, I wounldn't want to take my passport to the beach with me.
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