On Sun, 22 Mar 2015 23:22:42 -0400, "Mr. Luddite"
wrote:

The iPad I have has a GPS built in. As the guy in the video explained
it will receive the GPS signal and work with Navionics even if you don't
have a 3G connection or have it shut off. That's how I understood what
he said.

===

That's the way Navionics on my smartphone works as long as you've
downloaded the charts you need in advance. I do that at home on my
wifi connection by going to the areas I'm interested in and zooming in
for maximum detail. After that, the charts for that area are
permanently stored.