River and fish finder

Might be a dumb question but.

When jigging below the lock and dam's on the Mississippi for walleye and sauger, do they typically show up on your fish finders, or are they hugging the bottom so tight that they dont show ?

Last year my Hook5 did not show hardly anything, and in trying to adjust the sensitivity I got a screen full of dots. 

Me and technology dont get along very well .

Thanks in advance 

There are more accurate fish finders out there than the Hook Series from Lowrance. I realize there's an expense to everything but you'll get more accuracy with a Lowrance Elite Series or a unit from Garmin or Hummingbird. 

I've had the same experience as James. Showed a jumble of timber reaching 4 to 5 ft off the bottom.  Couldn't tell if there was fish in there. Dropped a jig straight down into the timber and had 7 strikes in a row. Landed my 5 keepers and a couple got wrapped around the branches. No shorts!

What is your average depth that you are in?  If you are in let's say 9' of water, your bottom coverage is roughly a 3' circle on average.  As you can imagine, pretty tough to mark fish at that depth.  Honestly you are better off using your locator at that depth for bottom.

Fished rocks in Canada with two friends and a finder and saw no fish while getting snagged with bottom bouncers. I dropped down my camera and fish were there! Some of them were big. Had a similar experience on the Fox River by a rocky drop off. The tops of rocks and tree branches show up but fish down below can remain hidden in the "shade"of a sonar beam.