HumminBird 597 ci HD w/ Down Imaging - Settings for Jigging

[Guppy35]

I currently have a HumminBird 597 ci HD w/ down imaging on my boat, and i'd like to learn more about how to adjust the settings for vertical jigging on the finger lakes for lake trout.  I've always heard people say to look for marks on the bottom and to target those fish for jigging, but i'm not sure what settings are best to look for those marks on the bottom.  Any advice, YouTube videos, or articles on how to adjust the settings on this particular model would be greatly appreciated!

[Tg8]

I have that unit. 200hz, auto on zoom is fine, and depending on clarity of water, 12-19 for sharpeness


Sent from my iPad using Lake Ontario United