I am surprised that the Spot is on the no no list. The In Reach Explorer I carry has been through many countries, but always on airplanes. When asked I say it is a GPS, which is true. I don't even think about its sat texting and emergency beacon features, although when on a trip I also send at least one text a day. Thinking though, it has been on the Newfoundland ferry a couple of times.
Also, if you are headed for the bush before or after your trip, it would stink not to be able to bring your Spot.
Maybe ask again, and ask why? Perhaps it can be left with the Purser.