What is maritime roaming and how it works

When you are on board a ship in the open sea, your smartphone or cell phone should not work, because the cellular network signal is absent

In early December 2019, Italian mobile phone users (if not all, the vast majority) discovered that foreign roaming is not the only form of roaming that exists. Thanks to the opening of a procedure for unfair commercial practices by the Antitrust Authority, they have come to discover that there is also marine roaming.

The Competition and Market Authority, in fact, believes that three phone companies (TIM, WindTre and Vodafone) have charged their users for using their mobile devices while on a cruise without, however, providing any information or asking for any consent. At the same time, the Antitrust Authority also holds responsible the shipping companies (Grimaldi, Grandi Navi Veloci and Compagnia Italiana di Navigazione) that would not have informed their passengers about the possibility of additional costs in case of use of the smartphone on board.

So what is maritime roaming, how it works (and why maritime roaming costs so much) and, above all, how to realize if the cell phone is in maritime roaming or not. Let's find out together.

What is maritime roaming

When we are on board a ship, on the high seas and several kilometers away from the coast, our cell phones or smartphones could not work. Cellular network towers and antennas, in fact, have a limited range and 3G or 4G signal coverage stops a few tens of kilometers away from the coast. When you are beyond 30-50 kilometers from the nearest cell tower, therefore, your cell phone or smartphone should no longer pick up any signal and, therefore, should not work.

And this is where maritime roaming comes into play. Taking advantage of certain technologies, large cruise ships or ferries allow the use of mobile devices by hooking them up to a private cellular network, which works exclusively on board. Maritime roaming, therefore, allows you to continue using your cell phone even in the absence of signal coverage from your operator, just as happens when we are abroad and we are connected to the network of a foreign operator instead of our own.

How does maritime roaming work

To work, maritime roaming needs two things: one or more cellular signal repeaters on board the ship; a satellite communication channel that allows you to connect the ship's "private" cellular network with the land infrastructure. All traffic generated by cell phones on board the ferry or cruise ship is handled by this satellite channel, which acts as a bridge between land and open sea, so that communications are never interrupted. Obviously, the cost of satellite communications is very high and telephone operators (and cruise lines) "offload" it onto the accounts of users, who are not always informed of the additional costs they have to incur to make calls when they are at sea.

How to know if your cell phone is connected in maritime roaming

If you are at sea, on board a cruise ship or a yacht, and your smartphone has a signal and is fully functional, then it is (almost) certain that it is connected in roaming. It may happen, however, that some smartphones or cell phones report to be connected to a different network than the terrestrial one. A numeric string may appear at the top of the screen, indicating the type of network you are connected to; or the name of the ship, so as to make it even clearer that you are roaming at sea and should not use your device.