My brother and I both have the montana 700i and use them for backcountry snowmobiling. Is there a way to send mapshare between these devices so we can see each others location while in the backcountry? I know it will work if we have our app open on phones.

I do not think you can view each other's location based on tracking points on the Montana itself.

You can send an inReach message directly to another inReach user (using their inReach address) and include your current location in the message. The receiver can then view that location included in the message and optionally navigate to it. Maybe that would work for you?

Thanks! 

Does anyone know if the messages are sent over the gps network ?  A lot of places have no cell signal...

The message do NOT go via the cell network. (YMMV if you get tangled up with the MESSenger app...)

Messages ALSO do not go via the GPS satellites. The GPS constellation provides location information. It has nothing to do with messaging. Messaging services are provided by the Iridium constellation. 

Thanks! 

Any idea if the tracking invite to friends works between the 2 units ? 

The singal location is great but wondering if another garmin can recieve the link to follow my tracks like i can do to a friend back home on thier cell when we are out in the mountains? 

No, the messages you sent directly from the Montana (or via the Explore app paired with a Montana) will go through the inReach satellite network. The GPS network is only for receiving location information.