Does WhatsApp work on a cruise ship?

Yes, but only if somebody has paid for the ship's internet. WhatsApp has no way of reaching another phone except through the internet. There is no clever setting, no offline mode and no trick: no connection, no message.

What actually happens when you send one

Your message goes from your phone to WhatsApp's servers and back down to the other person. That journey needs the internet at both ends. On land your phone has mobile data and you never think about it. At sea there is no mast, so the only internet on the ship is the satellite connection the line sells you.

Send a message without it and you get the little clock icon. It sits there. The moment anyone's phone joins a network — the ship's wifi, or a port's — the whole backlog goes at once, which is why people come back from a day ashore to forty messages arriving in a heap.

The part that catches families out

Everyone has to pay, not just you. A package is usually sold per device, so a family of four wanting to message each other across the ship is four packages. People discover this at the point they are trying to arrange where to eat.

It is also worth knowing that a cheaper tier sometimes blocks calling even though messaging works. If you were planning to ring home, read what you are buying.

What works when nobody has paid

For reaching people at home, nothing does. Satellite internet or a port's wifi are the only ways off the ship, and both cost something.

For reaching the people you are travelling with, which is what most of this is really about, you do not need the internet at all. CruiseLink passes messages straight between the phones in your group over Bluetooth and the ship's own local network. No package, no account, free.

The honest limits: it only reaches the group you set up, everyone needs it installed before you sail, and a message travels when phones come near enough — directly, or carried by someone else in your group — so it is not instant across a whole ship.

If you are buying a package anyway

• Put the phone in airplane mode first, then turn wifi on by itself. That keeps you off the ship's mobile mast, which bills as roaming and is where the horror stories come from.
• Turn off photo auto-download in WhatsApp's storage settings. A satellite link is slow and shared, and a family group sending holiday pictures will flatten it.
• Don't buy four packages to talk to each other. Buy one for the outside world and use something local for the people on the ship with you.

Get CruiseLink

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