Originally Posted by Howesounder
Navionics on a phone does not need cell coverage I think. Pretty sure the gps part works independent of cell service. Can not imagine going far without at least that.
Exactly. Navionics does not require cell or wifi to work once you have the app and you've downloaded the chart that you need. We use it throughout the Bahamas and Caribbean in places where we are days away from any cell service.