Sims, eSims and Cruises.

What I learned trying to remain connected on a cruise around the Caribbean.

I was looking just for connectrivity onshore at destinations, but there are eSims that allow you to connect to the ship phone system while at sea. This is distinct from the ships wifi network.

Phone systems on cruise ships, native and 3rd party

If you buy a package from your cruise ship, or directly from the mobile provider such as Telenor Maritime, you will probably pay a load of money.

If you buy a 3rd party sim that is compatible with your ships phone system it will probably be a load cheaper.

e.g. https://esim.redbullmobile.com/internet-on-cruises/

eSims

These are virtual sims. They are code, or "software" rather than "hardware", but in many ways they are no different from physical sims.

You can buy an eSim that may already have credit or one with no credit that you need to topup.

Typically they are cheaper than a physical SIM as the supplier doesn't have to stock or deliver any actual hardware.

Also you don't have to wait for a physical delivery which may be diffcult for you in terms of timescales or locations.

eSims will often be ready to use minutes or hours after purchase.

eSIMDB is a good site for finding eSims for many locations: https://esimdb.com/

I found eSims on eSIMDB that gave me 2Gb for one day in several Caribbean locations for around $1. YMMV.

eSims and profiles

It's 2026. Many newer phones support eSims. Many older phones don't. Read the manual. If your phone doesn't support eSims, read the next section called "SIM adapters simulating eSims"

My phone only supports one eSim, however this one eSim can hold multiple profiles, at least 4 in my case.

Each profile is an eSim that I bought for a particular country, although there is no reason you couldn't have more than one profile supporting a single country/region.

Be aware that typically only one profile can be active at any one time. Typically the physical SIM and one eSim profile can be active simultaneously.

SIM adapters simulating eSims

It's possible to buy a physical sim card that can be configured to operate with at least one eSim profile. This means that it can be used in a phone that isn't eSim compatible.

There are a few of these "eSim adapters". I list some below without any comment on how well they work; you need to do your own research.

Name	Notes	Link
EIOTCLUB		https://www.eiotclub.com/products/esim-reader?variant=41122786377861
9eSIM		https://www.9esim.com/
JMP	Open source	https://jmp.chat/esim-adapter
eSIM.me	Seems to be some kind of licensing model??	https://esim.me/
5ber	Possibly defunct?	https://esim.5ber.com
ESTKme		https://store.estk.me/

Configuring the eSim adapter

There seem to be two primary ways of doing this.

One is with software - typically an app that runs on your phone.

The second is with a hardware "reader" (often USB) that configures the sim. You put your eSim adapter in the reader, plug it into a computer, run the accompanying software and you can load your eSims onto the eSim adapter via the card. Once done, remove the eSim adapter and put it in your phone.

Obviously the first approach os the easiset as it doesn't require any extra hardware beyond the adapter.

Apps for configuring eSims

Name	Platform	Notes	Link
EIOTCLUB	Android, Windows		https://play.google.com/store/search?q=eiotclub&c=apps https://cdn.eiotclub.com/esim/pro/full/EIOTCLUB_eSIM_reader-windows-x86_64-with-lpac.zip
NekokoLPA 2	Android, iOS, macOS, Windows, Linux, Chrome		https://lpa.nekoko.ee/en
OpenEUICC and EasyEUICC	Android	Make sure you understand the differences between these two, especially that OpenEUICC needs to be installed as a system app: your phone will need to be rooted.	https://github.com/estkme-group/openeuicc/blob/master/README.md

Good luck!