Brent, we too in 2015, as we cruised together, used the iPad with Navionics with the US & Canada as our primary & again did so in 2016, but last summer, while up there it started glitching. Following a complete shutdown, while at a port it wouldn’t upload the maps. I had two ipads & it did the same on both, fortunately never at the same time. Last fall it worked well at Lake Powell, but I suspect if we want to use it on our next planned SE Alaska cruise in 2020 it will have to be by yearly subscription if at all. Garmin has quit the blue chart app downloads too. I had them both & though preferring Navionics, the Garmin blue chat app worked well also. They are also shutting down their rode map apps. I have the Garmin NAVIGON app & really liked it on the iPad for road travel.
I think Garmin has come to the conclusion that offering a $50 app on a IPad that worked as well as many expensive chart plotters was not good for their primary business of making & selling plotters & have no problem with screwing over the customers that purchased them.