Many of my friends use the I-Pad as their source for charting for both Aviation as well as Boating. We recently downloaded a Navionics chart system for our boating as well as Aviation Charts for our Airplane. The first step was loading the Aviation Charts for the plane. We soon realized that they worked great when we had Wi-Fi but as soon as we lost the Wi Fi connection we lost the GPS that put our location on the charts. I contacted a friend in the Aviation industry and he directed me to buy a Bad Elf GPS antenna. Plugged it into the Ipad and it works. Now as we travel whether by air or water our location is transposed to the charts. The charts were found in the APP store and a payment was required. In one situation while traveling from the Bahamas to Georgian Bay in the Great Lakes we ran to the edge of the chart and had to download another chart. We were able to do so by turning our Hot Spot on our iPhone and downloaded the next chart. My next pursuit will be to get an Ipad with a GPS built in. This should take the place of the BAD ELF. But that may not happen soon as the Bad Elf is working great.