I have a Humminbird 597ciHD Combo fish finder and I know I'm not getting full benefit from it because I'm a speed bump on the technology super highway. Having said that, I understand that Navionics has a chip I can insert in my unit that will give me better lake detail than what I currently get. My question is which chip should I get? I was looking at the Navionics site and the map for Florida is chopped off right above/north of Lake Lochloosa. I would like to get something showing more north Florida lakes. Any thoughts?

Thanks.