4. Cruise ship Wi-Fi options: Apply only to select cruise lines and ships. Packages cannot be sold to customers traveling on non-qualifying cruise ships / lines. Compatible device with domestic postpaid wireless service required. One-time charge applies. Packages are valid for 30 days beginning on the chosen effective date, may cross 2 bill periods, and expire automatically. Packages won’t be prorated if canceled on or after the chosen effective date. Packages canceled prior to chosen effective date won’t incur the one-time charge. After expiration, pay-per-use rates will apply unless a new package is purchased. Cellular at Sea, Nor-18 or 901-18 display: Onboard networks operate only while in international waters. Therefore, your AT&T cruise package allowances and overage rates for on-ship usage only apply when Cellular at Sea, Nor-18 or 901-18 displays on your device. Cruise package allowances and overage rates also apply off-ship, but only to the extent that you're attached to land-based cellular networks in Mexico, Canada, and select Caribbean islands, and have no other AT&T domestic and/or international calling, texting and/or data plan that supersedes those rates. Everywhere else (including where Cellular at Sea, Nor-18 or 901-18 isn’t displayed), pay-per-use rates apply, unless an additional current package offer applicable to country visited is active on the line of service. Cruise ship options are designed for use onboard cruise ships while at sea; therefore, usage onboard a cruise ship is required. The international data offer must be added to an existing domestic data plan. Messages received while roaming are billed at applicable domestic rates. Available only through AT&T Customer Care; these options aren’t currently available in store or online.