The two networks behind every cruise eSIM

Why only two maritime networks exist

Putting a mobile network on a ship is not a software problem. It means installing base stations inside a steel hull. Those base stations need backhauling by satellite. It also means striking roaming deals with hundreds of land-based carriers. That way, a passenger from any country can connect. And it means holding the maritime spectrum licences needed to operate outside national waters at all.

All of that adds up to a decade of spending and regulatory work. That’s why the market has two suppliers rather than twenty. Wireless Maritime Services is the larger one. It’s a joint venture that has been fitting cruise ships since the mid-2000s. Your handset reports it as network code 901-18, under the name Cellular at Sea. Telenor Maritime is the other. It’s the maritime arm of the Norwegian operator. It dominates the European fleets and the North Sea.

Every consumer eSIM brand you can buy for a cruise is a reseller. It resells one network, or both. None of them owns a ship transmitter. That’s not a criticism. Reselling is how the whole travel eSIM industry works. But it does change what a comparison between brands actually means.

Why metered prices are nearly identical

Look at the metered plans from Saily, Voye Global and GigSky and a pattern jumps out. Half a gigabyte for a day runs $16–19 across all three. A gigabyte for a week runs $28–31. Three gigabytes for a month runs $49–55. Ten gigabytes runs $108–119. Four brands, different apps, different support, different marketing — and they land on the same numbers.

They aren’t colluding, and they aren’t copying each other. They’re all buying the same wholesale gigabytes from the same network. They pay similar rates and add similar margins on top. The ladder belongs to the network, not the brand.

Here’s what that means in practice. On a Cellular at Sea ship, choosing between those brands on price alone means choosing between rounding errors. What actually differs is everything around the data. Can you test the plan before paying? Does it cover your port days too? Is there a coupon? Does anyone answer when it stops working?

Prices do genuinely diverge at the edges of the ladder, though. Unlimited-by-duration plans are a business decision, not a wholesale one. That’s why OneRoam and Maya look nothing like the metered field. Telenor Maritime resellers price on a completely separate ladder, too. Red Bull’s EUR 5 for 250MB has no equivalent on the Cellular at Sea side. And eSIM.dog’s cost per gigabyte runs several times higher than anyone else’s.

How to identify the network on your ship

This is the question the whole page exists to answer. There are three ways to settle it, in order from least reliable to most.

First, the rule of thumb. Mainstream North American fleets are mostly Cellular at Sea: Royal Caribbean, Carnival, Norwegian, Princess, Celebrity, Disney, MSC, Holland America. European operators are far more likely to run on Telenor Maritime: AIDA, Costa, P&O Cruises, Cunard, TUI/Marella, Viking Ocean. So are the big ferry fleets — Stena Line, DFDS, Brittany Ferries and Color Line.

Second, the check. A provider’s own vessel list either names your ship or it doesn’t. This is more reliable than the rule of thumb. Fleets get transferred between brands, and a Carnival Corporation ship can end up on either network depending on when and where it was fitted. Carnival Firenze and Venezia, for instance, are Telenor vessels sitting inside an otherwise Cellular at Sea fleet.

Third, the proof. Sail past twelve nautical miles, open your phone’s network settings, and read the operator name. WMS ships report "901-18" or "Cellular at Sea". Telenor ships report "Telenor Maritime". That’s definitive, but it’s also unhelpful — you only get it once you’re aboard. Which is the strongest practical argument for buying from a provider that lets you test before you pay.

Why the ship network starts twelve miles out

A ship’s network doesn’t switch on by timer, and the captain doesn’t decide either. It switches on when the vessel leaves territorial waters. Under the UN Convention on the Law of the Sea, those waters extend twelve nautical miles from the coastal baseline.

The reason is licensing, not engineering. Inside those waters, the radio spectrum belongs to the coastal state. It’s licensed to that state’s national carriers. A ship switching on its own base station there would be transmitting on somebody else’s frequencies. So the equipment has to shut down as the vessel nears the coast. It can only power back up once it’s outside.

This creates a gap that few vendors mention. For roughly the first hour after leaving the terminal, the shore towers are fading. The ship’s network isn’t legally allowed to operate yet, either. Neither your land eSIM nor your maritime eSIM works properly in that window. That’s not a fault. It’s a treaty.

It’s also why a "cruise" plan that runs on land networks isn’t just worse. It’s a different product altogether. It can never reach the ship’s network, because it has no roaming agreement with a maritime operator. No amount of signal strength changes that.

Choosing a provider once the network is known

Start with the network, then choose your provider within it. Pick a brand first and hope it covers your ship, and you’re gambling. That’s how people end up with a plan showing no service on day one.

On a Cellular at Sea ship, you get the widest choice and the smallest differences between brands. GigSky covers it with the widest vessel list, port coverage on the Cruise + Land plans, and the only free trial in the market. Saily and Voye Global undercut it per gigabyte, but they’re sea-only — budget for a second eSIM ashore. OneRoam sells unlimited-by-duration plans covering ship and land together, which suits heavy users who’d rather not count gigabytes.

On a Telenor Maritime ship, the field narrows sharply. GigSky reaches many of these vessels — it’s the only brand on both networks. Where it doesn’t reach, you’re down to two realistic options. Red Bull MOBILE has the most complete named-fleet list published anywhere. eSIM.dog is pricier per gigabyte but reaches European operators nobody else lists. Telenor also sells directly through its own app.

And if your ship appears on both networks’ lists, the network stops mattering. The ordinary comparison takes over: trial, port coverage, price, support.

The one provider on both networks

GigSky is the only brand in this market selling across both wholesale networks. The table above shows that rather than just claiming it. Its mainstream cruise range rides Cellular at Sea. Its ferry plans ride Telenor Maritime.

The result is coverage that doesn’t depend on you identifying the network correctly. A Royal Caribbean sailing and an AIDA sailing sit on different networks, and one provider covers both. Add the free 100 MB trial, and it’s the only plan you can test on your own ship before paying anything. On a product whose failure mode is "no service on day one", that’s worth more than a few dollars per gigabyte.

The trade-off is price. GigSky isn’t the cheapest per gigabyte on either network. Saily and Voye undercut it on Cellular at Sea. Red Bull undercuts it at the entry level on Telenor. If your ship sits comfortably on one network, and you’re disciplined about buying a second eSIM for ports, a cheaper brand on that network will do the job just as well.