How to chat on a cruise ship or ferry with weak or paid Wi-Fi

On a ship or ferry you can message the people travelling with you without paying for Wi-Fi, provided they are nearby and also run the same Bluetooth chat app. It does not connect you to anyone on land.

Why ships are awkward for messaging

Out at sea your phone usually has no mobile signal, so messaging depends on the ship’s Wi-Fi. That is often slow, shared by many passengers or sold as a paid package. Ferries on short crossings can be better or worse, depending on the route. For a family that only needs to say “we’re by the pool, come up”, paying for a connection feels like a lot.

Free options first

If you do have ship Wi-Fi or a signal, iMessage, WhatsApp and an ordinary phone call keep working as usual, and they reach people anywhere. Some ships also have their own onboard app for chat or calls. Check what your ship offers before you pay for anything.

Where Flight Mode Chat fits

I build Flight Mode Chat, so take this part with that in mind. The app chats with nearby people over Bluetooth Low Energy. It needs no internet, no servers and no SIM. You can send text, images, voice notes, files and contacts, in private chats or public channels, and everything is end-to-end encrypted. It runs on iPhone and iPad, so a tablet in the cabin works too.

Because the app finds nearby users automatically, you open it and see who around you has it. For a family it means:

• Telling a teenager in the arcade where the rest of you are sitting.
• Sending a photo of the sunset from the deck to someone sitting inside.
• Saying “we’re back at the cabin” without buying a package.

What it cannot do

This part matters more than the list above.

• Both people need the app. Install it before you board, while you have a normal connection.
• It reaches nearby phones only. A ship is large and made of a lot of metal and walls, so do not expect it to cover the whole vessel. I won’t give a distance, because it depends on where you are standing.
• It cannot send an SMS or iMessage, and it cannot reach anyone ashore.
• It is no replacement for the ship’s emergency arrangements. Follow the crew’s instructions.

Before you sail

1. Install the app on every phone and tablet in your group.
2. Open it together once and confirm everyone sees everyone.
3. Agree on a fixed meeting spot in case someone drifts out of reach.
4. Try it between two parts of the ship early on, so you know where it works.

Related guides

For other no-signal trips, read messaging at festivals and on trails. If you are curious how the Bluetooth part works, see the Bluetooth chat app for iPhone, and for a comparison of options, offline messengers compared.