When the ship is sailing on international waters, you will be able to use the WMS network for incoming and outgoing calls, SMS, and Data services (email and web surfing). Once in port, you can connect to local roaming networks as permitted by your home carrier.

Data roaming does work on a cruise ship, but it is notoriously expensive and potentially risky for your bank account. When a ship is at sea, it connects to a specialized maritime satellite network (often showing as "Cellular at Sea" or "901-18") rather than land-based towers. These networks are not typically covered by "unlimited" international roaming plans from carriers like Verizon or AT&T. If you leave roaming on, your phone will automatically download data at astronomical rates, sometimes costing $10 to $20 per megabyte. In 2026, most experienced cruisers keep their phones in Airplane Mode and use the ship's Starlink-powered Wi-Fi packages, which have become faster and more affordable. If you must use roaming, you should purchase a specific "Cruise Plan" from your provider before departing, but even these are often limited in data and very costly compared to the ship's internal Wi-Fi options.