Autochart Live is either saved to internal memory in the unit ..... about 8 hrs data limit on that ..... or a Zero lines Card. You can do sonar recordings to a regular SD card ... but not Autochart Live.
https://www.amazon.com/Humminbird-El...ero+lines+card
P.S .... Waypoints are saved and used from the units internal memory ... except for snapshots if you have that option turned on. You can export your waypoints to an SD card for backup purposes, and that is a good idea .... but the waypoints that are actually being used are in the units memory.