Sint Maarten eSIM

It depends on which territories the plan lists, because the Dutch and French sides count as separate destinations on the network even though you can drive across without stopping. If you plan to spend time on both, check before buying whether the plan covers each of them. The other option is to set network selection to manual so the handset does not drift onto a side you are not covered for.

The island is narrow and towers on both sides are within easy reach of each other, so the handset simply picks the strongest signal at that moment, which can belong to the other jurisdiction. The fix is to open mobile network settings, turn off automatic selection, and choose an operator on the side your plan covers. If you lose service entirely, switch back to automatic briefly and then set it again.

For a there-and-back day, usually not: you are only ashore for a few hours and can keep data off while you are there. Save the return ticket, the meeting time and the map to your device before you sail. If you intend to stay overnight or work from the island, look for a plan that names it directly, because both are separate destinations from Sint Maarten.

Most plans here start when the phone first connects to a network at the destination, so you can install in advance at home and switch it on after landing. Each plan page states its own rule.

No. The eSIM is a second line, so you keep your home number for SMS OTP. Turn off roaming data on the home line and set the eSIM as the data line.