Do eSIMs work on a cruise ship?

An ordinary travel eSIM does not work at sea. It connects to mobile masts on land, and in the middle of the ocean there are none. It works in port, usually for a few miles off the coast, and then it stops. Anyone telling you otherwise is selling one.

What an eSIM is actually good for on a cruise

Ports. That is the honest answer, and it is a genuinely good one.

A regional eSIM for the Mediterranean or the Caribbean gives you data the moment you step ashore, at local rates rather than your provider's roaming rates, with no faffing about finding a café's wifi. If your itinerary is port-heavy that is real value, and it is usually cheap.

What it will not do is keep you online on a sea day.

The maritime plans, and what they really cost

There are eSIM plans that work at sea. They do it by using the ship's own satellite-backed mobile service — the same one that generates the roaming horror stories — and they are priced accordingly.

If you genuinely must be reachable mid-ocean, compare one honestly against the ship's wifi package. The wifi is usually better value, and on a newer ship with a low-orbit satellite service it is usually faster too.

The mistake worth avoiding

Installing an eSIM does not protect you from maritime roaming. Your phone can still find the ship's mobile service on its normal SIM and connect to it without asking, and that is where the big bills come from.

Airplane mode, on, as you sail. Turn wifi back on by itself if you want it, and switch the eSIM's data on when you are ashore. The full explanation of how those charges happen is here.

If what you want is to reach your own party

Then none of this applies, and you do not need to buy anything. CruiseLink passes messages straight between the phones in your group over Bluetooth and the ship's local network, with every phone in airplane mode. It is free.

The limits, plainly: it reaches only the group you set up, everyone needs it installed before you sail, and a message travels when phones come near enough rather than instantly across a whole ship.

So, buy one or not?

• Lots of ports, and you want maps and messages ashore — yes, a regional eSIM is good value.
• Mostly sea days — no. It will be switched off for most of your holiday.
• You need to be reachable at sea — compare a maritime plan against the ship's wifi, and expect both to be expensive.
• You just want to find your family at dinner — you do not need either.

Get CruiseLink

Free, no account, nothing to set up beyond your group. On iPhone and Android, and the two work together.