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How Cell Phone Service Works on a Cruise Ship
Your regular phone works at sea because the ship carries its own cellular network. This page covers how the connection works, what to do before you sail, and what you’ll see on your screen.
What to do before you sail
Three checks set your phone up for Cellular at Sea: your ship, your carrier, and your roaming settings.
Check your ship.
Service works on ships in the Cellular at Sea network; the coverage and partners page has details for major lines.
Check your carrier.
Your usage at sea is billed by your home cellular carrier under its roaming terms, so ask what your plan includes for cruises before you sail.
Turn on roaming and data roaming.
Both need to be enabled for data to work on your phone.
For the full step-by-step, see getting started on the What Is Cellular at Sea page.
The ship is the tower
On land, your phone talks to the nearest cell tower. At sea, on ships in the Cellular at Sea network, the ship itself carries cellular equipment that does the tower’s job for everyone on board. Because the equipment is on the ship with you, the cellular signal on board activates when you are in international waters, about one hour from port. With roaming on, you don’t need to do anything else to use it.
The satellite carries it home
Cellular at Sea’s shipboard network connects to land through a satellite link. When you communicate via Cellular at Sea, the call, message, or data travels from your phone to the shipboard network, then to a satellite, then to a ground station, then to the Wireless Maritime Services (WMS) core network, and into the recipient cellular carrier’s network, in moments. When you are the recipient, the same path runs in reverse to reach you at sea.
Your phone
Shipboard network
Satellite
Ground station
WMS core network
Recipient carrier’s network
All of this is automatic; your phone handles every hop on its own.
What happens near ports
Close to shore, regular land networks come back into range, and your phone treats the trip like any international travel: it connects to local networks in port, under your plan’s roaming terms for that country. The Cellular at Sea shipboard network operates out at sea, in international waters, about one hour from port. Roaming and data roaming need to be enabled for data to work on your phone. Beyond that, no settings change from the traveler’s side; the phone moves between networks on its own.
IN PORT
OUT AT SEA
ROAMING
Wondering about the bill instead? See how roaming charges work.
What you’ll see on your screen
At sea, your phone’s network name may display Cellular at Sea or 901 18, depending on your device. What appears on screen is set partly by the network and partly by your SIM and phone manufacturer settings. If the name looks unfamiliar mid-ocean, that’s the shipboard network doing its job; the 901 page explains the code.
- 901 18
- Cellular At Sea
FAQ
Why does my phone work in the middle of the ocean?
Because ships in the Cellular at Sea network carry their own cellular network, linked to land by satellite. Your phone connects to the ship’s network the way it connects to a tower on land.
Do I need to do anything to connect at sea?
With roaming enabled, your phone finds the shipboard network on its own once the ship is at sea. Be sure to toggle Wi-Fi off when you want to use cellular data for the internet; you can toggle it back on if you need to use Wi-Fi. Billing runs through your home cellular carrier; see how roaming charges work.
Why did my service change when we left port?
Near shore, your phone uses local land networks. Out at sea, the shipboard network takes over. The switch is automatic in both directions.
Is the connection different from my service at home?
The mechanics are the same from your side: connect and use your phone normally. At sea everything travels over a satellite link, and your usage is billed by your home cellular carrier under its roaming terms, like usage in a foreign country.