Hi. I have cruised to the Carribbean and on the last cruise I took an AT&T international calling card, and I was able to use it on only two ports. On the other ports, I had to buy a pre-paid card ($5, $10) in order to be able to use a pay phone because AT&T did not service those areas. I used my credit card once and they charged me an arm and a leg - so this should not be an option unless it's an emergency. So, you can take an international calling card but be prepared to purchase another at the port if you are not able to use it. Also, there's always the option of e-mail on board and at port. Hope this helps.