I know nothing about the Great Lakes.
However for HB finders it’s hands down, Lakemaster.
I see they have the Great Lakes card, not sure if that covers what you want?
I’m sure Just Steve, and some of the others can really offer advice.
I’m just filling in until someone with real knowledge comes along! LOL

https://humminbird.johnsonoutdoors.c...great-lakes-v2


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