Fished a tournament over the weekend - Lake is 595 acres with maximum depth at around 42 feet and average depth at around 17 feet.  Water temps were 83* at the surface.  While pre-fishing on Friday I noticed that when I was at 16' to 18' I would see a line of fish holding at 13' - it looked like they were lined up nose to tail.  If I pulled out deeper the fish remained concentrated at 13' but would also show up higher in the water column but none at the surface and none below that line.

Was this the thermocline?  And how do you get 'em to bite at that depth.  BTW, tournament was won on a Chatterbait in 3'-4'.  Thanks for any input.

from my experience it would be hard to get them to bite, you could throw a crank, jig, soft plastice, or sometimes a jerkbait will work.  you just have to make them think it is a super easy meal so they will nail the biat.

Probably was. My lowrance units show a thin line across the screen. Just depends on how you have your unit set up as to how it will show.

Here are my settings:

Ping speed               75

Noise Reduction       Low

Surface clutter         Low

Color line                 72-74

Chart speed             100

Sensitivity  Console  Auto

                  Manuel   72-78

Good luck

probably was, I would suggest you turn off the cartoon fish symbols on your graph too. it will be easier to tell what is what down there.

+2 on the suspending jerkbaits. Get one down to their level and just let it sit. Give it some jerks on slack line and turn it around and they will smash it!

It would be interesting to know what the temp. was @ 13 FOW.  Sometimes having the ability to use a probe would be a big help.  I've got a small battery operated one with a 50' cable that let's me figure out how deep various temps are at.

The next thing to worry about is dissolved oxygen at that level. 

Yes it was. I'm an assistant catfish guide on the James River. One day last week we weren't catching s#!t and it was like 100 out. Our clients were bored so me and my buddy Billy Nicar decided to just swim in the deep hole. I got some diving goggles and was swimming around, following a couple smallies and a 25# flathead. I was in probably 7 FOW and swam all the way to the bottom, and the thermocline was so cold I just layed there for about a minute ;D