Depth Finder Help

I'm a speed bump on the information super highway. And it's not a good thing when it comes to trying to figure out how to use the depth finder my wife gave me some years back.

It's Humminbird 597ci HD Combo.

Some way or other (according to a buddy of mine) I should be able to pop some sort of SD card into it and all sorts of wonderful things happen.

A brochure that came with said that within 2 months of purchase to go to navionics.com and plug in a chip and click on downloads and updates. Well, that didn't happen.

So if there's anyone here who can sorta explain what I got and what it can do with charts and stuff I would appreciate it. Or tell me some place to go to.

I like the rig. But I'm just using it for water depth and to find my way back to the ramp.

Thanks.

Here's the compatibility Chart for Navionics ...:
https://dbe2w38xsulyl.cloudfront.net...ilityGuide.pdf

Here's the regions list for LakeMaster ...:
https://www.humminbird.com/general.a...d=1321&id=5847

LakeMaster adds a few features to HB mapping that Navionics doesn't ...

Rickie