sonar reading grass tops as lake bottom

[txchaser]

My Helix sometimes reads the grass tops as the depth. Pretty clear on the DI that it's not 2ft deep, it's 6ft, as an example.

Mostly irritating when I'm trying to map an area with Autochart.

Tried fiddling with sensitivity, clarity, etc, no change. Emailed Humminbird, they didn't really have much for me.

Is this just how it is sometimes and I need to get over it?

 

[WRB]

Not that familiar with mapping sonar but false bottom reading  is easily determined by the secondary echo reading. It should something you can adjust using the power setting. Go back to Hummingbird and talk to a rep that knows what they/are talking about.

Tom