It is my unpleasant duty to assist with phone management at work; and the Service Suprise that really knocks people for a loop is getting in range of a cruise ship’s cell tower if you are sufficiently close to the port and the local RF witchery causes your phone to consider roaming to it to be the best option.
We have a pretty decent corporate account, so a lot of roaming to countries our staff commonly visit is fine; but the shipboard networks don’t really do polite cooperation regarding data rates; both because they have satellite backhaul to pay for when at sea; and because cruise ships are full of the intoxicated and cost insensitive so why not go high?
Luckily it happens infrequently enough that our rep will sometimes just comp it just in the spirit of not having us thinking of that time a C-level managed to spend ~$1000 doing some perfectly pedestrian normal phone data stuff at a harborside hotel or restaurant.