The short version: airplane mode at sea, a regional eSIM at port, and your main line's data roaming off the whole trip. Here's why, and what each option really costs.
Assuming 5 port days, one phone.
| Option | Rough cost | Catch |
|---|---|---|
| Regional travel eSIM (e.g. EveryPort) | From $10.99–$18.99 once | Port days only, not at sea |
| Carrier day pass | ~$12 × 5 = ~$60 | Charged per line, per day |
| Ship WiFi package | $25–35/day | Satellite speeds; priced for the whole voyage |
| Cruise-line eSIM bundle | ~$18 for 0.5GB | Tiny data allowance |
| Ship's maritime cell network | Can be $$$ per MB | Connects automatically unless you're in airplane mode |
No. Land-based networks reach only a few miles offshore. At sea your options are ship WiFi or the ship's own maritime cell network, which is billed by your carrier at premium rates. Use airplane mode + WiFi at sea.
Many ships run their own cell network for when you're out of range of land. Your phone can connect to it automatically, and your carrier bills it as a premium roaming network, often several dollars per MB. Airplane mode at sea prevents it.
Yes. Keep your main line on for calls and texts with its data roaming off. The eSIM handles data, so WhatsApp, FaceTime and iMessage work over it at port.
If you only need one or two port days, a carrier pass can be simpler. Past three port days, or with more than one person, a regional eSIM is almost always cheaper.