Download and install Humminbird Chart Select to your computer.
With that software you create an account to purchase and download a single body of water that is HD.
To do that you have to put an Encrypt folder on a blank formatted memory card of 32 GB or less in capacity.
You use your Humminbird unit to put the encrypt folder on the memory card.
The body of water file has the contour map, several years of satellite overlays, USGS map overlay, and SmartStrike you can add to the purchase.
Humminbird Helix 12 CHIRP SI, 1198c SI, 1198c SI, ONIX 10 SI NT, Helix 7 CHIRP SI GPS G2, SOLIX 12 SI, 360, RC-1