this happens a lot on road trips...you always go through the pockets of low reception areas in the middle of the farm fields
so......
what happens when you lose reception?
There's not just one nav app out there. I assume you're referring to Google Maps Nav. Without data, as others have pointed out, you don't get maps. If you need maps in areas without coverage I suggest looking into nav apps that store map data locally (e.g. CoPilot, etc).forgive the stupid question. what happens when you drive through an area you don't get service?