Helix 7 finder question

[fish/hunt4ever]

I know this is not ice related but could be for finding structure to go and fish during the ice covered months, so anyways I was looking at the mapping with this unit, which I have installed on the boat just did not play with it too much before ice, and was wondering on the micro SD card, do you have to buy the zero card or could you just go and buy a 32G Micro SD card and use it to map with?  Or does the zero card have some formatting for the Helix or any Finder that has the auto chart software that needs to be used to map with the fish finder?  Another question is that some people like using Genesis software to download the map for other uses and was just seeing what others like to use or do with their mapping, oh and I should say that the lakes that are around my state we only have like three that the Lake master chips kind of work on and so many around here say that mapping it yourself is better anyways. Thanks for any and all advice.  Have a safe end of the hard water season and a safe and good soft water season.

[gofishin]

No you can not use just a blank sd card. The zero line cards are loaded with over 5 million bodies of water, they just don't have any contour line. (Imagine a lake on google maps, not satellite image) Then when you use autochart, it fills in the contour lines for the lake you are mapping. The zero card has 16GB of info on it and 16 GB of free space for you to use for mapping. Hope that helps.

[silverado23]

 you can use a blank 32 Gb card and upload data to Navionics. After navionics processes the data,
You can then see the contours with the phone app or on your hummingbird.

Details:
https://www.navionics.com/usa/support/tutorials/humminbird/sonar-log-recording

[VTMatt]

How much coverage do you get out of the free space though....?  Can you map a huge part of a lake???

[fish/hunt4ever]

From what I understand I can only map about 8 hours and from trying to map one lake that the deepest part is 30 feet and the part we fish the most is 15 or less and mapping that takes forever since you are not looking at a very wide angle at those depths so lots of passes to get a good start to a hump or something took 15 minutes or more to cover a 50x50 foot spot.

[silverado23]

Using Navionics logging settings for my helix 7  4 hours of data was about 20MB.   

[VTMatt]

Using Navionics logging settings for my helix 7  4 hours of data was about 20MB.

Hoping this is true!

[Drift Dodger]

Using Navionics logging settings for my helix 7  4 hours of data was about 20MB.

That seems much more reasonable. I've mapped many days and hundreds of acres with my Garmin EchoMAP and the total volume of contour data is 180 MB.

So could the high data usage through Autochart mapping be due to including additional bottom content or some other detail?