If you have postpaid service, yes you can text at the ports or onboard the cruise ship. No if you have prepaid. You pay international roaming rates for any usage, including texts. There are international plans that include texts. The cost to send a text without a plan is $0.50. Received texts are free. Make sure you turn cellular data or data roaming off. Data charges will run up a big bill very quickly. International plans and rates are here: https://www.att.com/offers/international-plans.html
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