will the Navionics app work on Lac Seul?

I’ve downloaded the Navionics app onto my Galaxy S3. I’d like to use it for navigation in the McKenzie Bay area of Lac Seul and was hoping someone could verify it works there. I’ve checked with my provider (Verizon) and with Navionics, but neither can tell me if it will or won’t. What I’ve learned is that, while a “real” GPS communicates directly with the satellites, the app on my phone needs to be able to pick up at least a faint signal from a cell tower.

I have a galaxy s3 with sprint and it worked great in northern lake of the woods this june. I did not have any cell service the entire week either. Now if only navonics would update their maps for NE LOTW…..