Meshtastic

You can chat with strangers if you wish. Coming from the amateur radio scene, I am quite used to doing this on a frequent basis, and it's a lot of fun to just see who is around and strike up a conversation. At night, we frequently get banned openings and you can see nodes from several hundred miles away.

Edit: My node is about the size of a credit card and just slightly thicker. And yet I'm able to chat with the router four miles away. I do admit, though, that not having the router nearby would make it less fun.

Edit 2: These radios can pick up stupid weak signals, so even if you could not get a message across the node information and location very well may get across. So if you needed to, you could change your long name to something like SOS, longitude latitude,