Short answer
Not always. If your US phone plan already includes the island you’re visiting, or you only need Wi-Fi, you can skip it. Otherwise a travel eSIM is usually the cheapest way to get mobile data: outside Mexico, AT&T and Verizon charge $12/day for every day you use your phone, while a short eSIM plan costs a few dollars for the whole stop. T-Mobile’s T-Mix More and Loaded plans (and the older Experience plans) include some data on every island here.
Your four options
- Your carrier’s roaming pass. You keep your own number for calls and texts. AT&T’s International Day Pass and Verizon’s TravelPass charge $12/day for each day you use the phone abroad. T-Mobile’s T-Mix More and T-Mix Loaded plans, and the older Experience More and Beyond, include 5 GB or 15 GB of high-speed data abroad at no extra cost. T-Mix Standard includes texts abroad but no data.
- A travel eSIM. You buy a data plan online before the trip and install it at home. It’s usually data only, and it runs next to your normal SIM.
- A local prepaid SIM. You buy it on arrival from a local network. Often good value for a longer stay, but you need a free SIM slot and time to find a shop.
- Wi-Fi only. Free, but only where there’s Wi-Fi: the ship, the hotel, cafés. Fine if you don’t need maps or messages while you’re out.
When you can skip the eSIM
- Your plan already covers the island. AT&T’s eligible unlimited plans and all of Verizon’s Unlimited plans include talk, text and data in Mexico at no extra cost, which covers Cozumel. T-Mobile’s T-Mix More and T-Mix Loaded plans, and the older Experience More and Beyond, include data in all 11 destinations on this site: 5 GB or 15 GB at high speed, then slow data at up to 256 kbps (15 GB or 30 GB in Mexico). Check which plan you’re on in your carrier’s app.
- You need your own number all day. Most travel eSIMs are data only. Messaging apps like WhatsApp and iMessage still work over the eSIM’s data.
- Your phone can’t take an eSIM. It has to support eSIM and be unlocked (check your phone).
- A short port day and Wi-Fi is enough. If you’ll stay near the port and can live without maps, the cruise terminal or a café may do.
What roaming costs compared with an eSIM
AT&T’s International Day Pass and Verizon’s TravelPass both cost $12/day in every destination on this site except Mexico, so a week costs about $84. A week’s worth of eSIM data usually costs less than that for the whole trip. The gap grows with the length of the trip and the number of phones: AT&T charges $6 a day for each extra line, and on a cruise ship’s network at sea its Day Pass costs $20 a day per line. AT&T never charges more than 10 daily fees per line in one bill period.
For one island in detail, with every carrier and local SIM side by side, see the Bermuda roaming charges guide and the Bermuda SIM card guide.
On a cruise: the one charge to avoid
At sea, your phone can connect to the ship’s own mobile network. Travel eSIMs don’t work there, and home carriers bill it at much higher rates than on land. Turn off data roaming on your home line before the ship sails, and only switch the eSIM on for data once you’re ashore. The Bermuda cruise guide walks through it step by step. To be online at sea, the Royal Caribbean, Carnival, Norwegian, MSC and Princess Wi-Fi guides compare the ship’s packages with a cruise eSIM.
What each carrier does on each island
| Destination | AT&T / Verizon | T-Mobile T-Mix More / Loaded (and Experience) |
|---|---|---|
| Bermuda | Day pass, $12/day | Included (5 or 15 GB) |
| Bahamas | Day pass, $12/day | Included (5 or 15 GB) |
| Cozumel (Mexico) | Included on unlimited plans | Included (15 or 30 GB) |
| Cayman Islands | Day pass, $12/day | Included (5 or 15 GB) |
| Jamaica | Day pass, $12/day | Included (5 or 15 GB) |
| St. Maarten | Day pass, $12/day | Included (5 or 15 GB) |
| Aruba | Day pass, $12/day | Included (5 or 15 GB) |
| Curaçao | Day pass, $12/day | Included (5 or 15 GB) |
| Bonaire | Day pass, $12/day | Included (5 or 15 GB) |
| Dominican Republic | Day pass, $12/day | Included (5 or 15 GB) |
| Roatán (Honduras) | Day pass, $12/day | Included (5 or 15 GB) |
For carrier prices and local SIMs on one island, see the phone guides for the Bahamas, Cozumel, the Cayman Islands, Jamaica, St. Maarten, Aruba, Curaçao, Bonaire, the Dominican Republic and Roatán, and Bermuda roaming charges.
Puerto Rico and the US Virgin Islands aren’t on the list: US carriers treat them as domestic, so you don’t need an eSIM there.
Common questions
Can I keep my normal number with an eSIM?
Yes. Your normal SIM stays in the phone. Turn off data roaming on it so it doesn’t charge you, and use the eSIM for data. Calls and texts to your normal number may still be charged by your carrier if you answer them abroad.
Is a local SIM cheaper than an eSIM?
Sometimes, for a longer stay. For a cruise stop or a short trip, the time spent finding a shop usually isn’t worth it, and you need a phone with a free SIM slot.
Do I need an eSIM if the ship has Wi-Fi?
Only if you want data on land. Ship Wi-Fi works on board (on Royal Caribbean it’s $18.99 to $24.99 a day per device: Voom prices by ship); ashore you need either the eSIM, a roaming pass or Wi-Fi in town.