I've a Garmin 168, which is the 162 with a depth finder too.

I have the hot spots package, and you can basically download an exact copy of a hot spots map. It even has the fishing areas and properties.

I love mine. It gets me right back to my spots.

One of the things I did was find an unmarked "channel" that crosses Lake Barkley's shallows from the channel to the LBL side. I am able to run my boat following my "programmed" route and I don't worry about bottoming out.

Now being the overly cautious guy I am, I did tend to idle the first several times to make sure it was accurate, and I still idle that route the first time each year after the spring floods to make sure there are no new trees lodged on the bottom.

Good luck,

Danny