Do mobile phones work on cruise ships?

Yes, you technically can but its not always possible depending on the amount of phone signal you have. When you do get signal, as mentioned above, itll be through an at-sea provider and will be considered a roaming charge by your network provider. Rates for these phone calls can be pretty high.

Can I use WhatsApp on a cruise?

Can you use WhatsApp on a cruise? Yes, but bear in mind video calling services such as Skype or messaging services like WhatsApp will use your onboard data if youre connected to the cruise ships Wi-Fi.