Scott this is the short explanation, lol:
You have to have the Autochart PC program to make 3D models & custom map overlays.
Scott this is the long one, lol:
Autochart Live is on the Humminbird units. That's what creates the charts with depth and contour lines you see on your unit as it records sonar data to the Zerolines card.
What most people miss is that this is intended to take the sonar data and create a custom map on your PC for lakes like mine that aren't on LakeMaster chips. It's on Navionics but the converted Autochart Custom map overlay is much more detailed.
You can just use the recorded sonar charts on the HB unit but you've probably already noticed that they lag as your boat moves along the water. You have to reach the end of the grid your in before it populates the next grid with recorded chart data. This is because HB uses outdated cpu's in the Helix units so they can get them very cheap. So the unit can't render graphics in color fast enough to keep up with your boat moving at 3mph.
To create the custom map overlays & 3D models of recorded sonar data you need to import & convert those files in Autochart PC or Autochart Pro DVD. These are the computer counterparts that create the Custom Map, Side Imaging & Base Overlays and send it back to your ZL card so you can select them as your map on the Helix unit. There are lots of videos on YouTube that shows how to do this.
The only difference between the 2 is with the Pro version you can import recorded Side Imaging files (SON002) Bottom Harness (SON003) & Vegetation (SON004) from the Record folder on the ZL cards to create a Side Imaging Mosaic overlay (this is literally looking at the lake bottom on the Helix) as well as the Map Overlay & Base Overlay. Both PC versions will create the 3D models.
You can see in the pictures below that the color chart data only goes so far but the custom map overlay (in Gray) populates the entire map. So you can scan the entire lake for fishing spots & waypoints without the lag of it loading chart data grid by grid.
Hope the pics help. First 6 are changing to the Custom Map Overlay. The rest I did a step by step from importing sonar data from card to converting to custom map and updating the ZL card with your new Lake Master and then the 3D imaging.
Sent from my SM-G965U1 using Crappie.com Fishing mobile app