The thermocline is not always at half the depth of the lake. It varies from lake to lake. You can see it on your depth finder. Or, if you want to get right on, get a good thermometer/drop line which will tell you the temperature at a given depth as well as the oxygen content and comes with instructions. An easy way to find it is to ask an experienced fisherman at your lake. Usually crappie and cat fishermen pay more attention to it than bass fishermen.

Thanks for all the info men. I will pay much more attention to all this in the future.

I went ahead and ordered one of the oxygen and temp meters from cabella although the reviews said they were cheaply made. I will let you know if it was worth the money.

good info