I am so so so happy to hear that. I booked a cruise to take my parents to Mexico, Jamaica and Cayman Island in June 2014. Mexico consulate website indicates that green card holder need a national passport to enter Mexico but it doesn't sound like they care for it. When getting on the ship here from the USA port, did custom and immigration officer asked for her passport? When I read the custom and immigration website, it said that from the US perspective, US only needs to see the green card to enter and exit the country but would like to hear from you who went on a cruise recently. My parents don't have their national passports . Did the US immigration asked for her passport?