I will never say never, but I have yet to see one in a current situation. Thermocline sets up when there is a drastic change in water temps. So Think of a cave. They are deep in the ground and have plenty of natural insulation from dirt, rock, etc. Caves stay a constant approx 55-75 degrees yr round no matter what the outside weather is. Why am I telling you about a cave???? Water does the same thing. Its an awesome insulator. So after about, im guessing here, 12-20 feet deep the water temp stays a constant approx 55-75 degrees. Knowing this explains alot of things. Why is there no thermocline in the winter??? Well the difference in the surface temperature and the temp at 12-20 foot deep is not all that different. Why is there NOT thermocline in the spring and late fall??? Same as the winter month. Now why is there one in the summer? Because surface temps get 90 degrees+ and then it rapidly changes to 55-75 degrees at approx 12-20 feet deep (depending on the lake) and it creates a ton of turbulance. As a thermocline just starts to establish early in the summer it may be relatively shallow. As the the surface temp of the water gets hotter and the summer goes on, the thermocline will get much deeper. Some say that there is no oxygen at and beneath the thermocline, I dont know about that, but I would say thats a good hypothesis since very few fish are found beneath it once it sets up. But It could just be an uncomfortable environment for the fish or the fish's food that makes them not want to be there. But after learning what I have just shared with you it NARROWS my search drastically for summertime crappie.

Now why have I not found a thermocline in a current situation. My thinking would be that the water is constantly flowing and mixing the cooler water with the warmer surface water making it over all a constant temperature. I recently a lake that had a thermocline where I was fishing and noticed the closer I got the dam that thermocline dissappered even in 40 foot of water. Well they were releasing alot of water from the lake at the dam, and this further explains what I think happens in current situations. Because with the flow out of the lake it created current.