When we travel in groups, the best way to keep in touch is with a “walkie talkie” or HAM radio. Most of us have our license and can help you obtain one so we are all in compliance.
This is our radio of choice, I have the programming cable, USB charger cable, and better antenna on my main radio, so if we ever meet I can program you to our channel.

I currently have two in case someone traveling needs one or one runs out of batteries.
Let me know if you have any questions!