I've been hearing alot about thermocline. What is it? Is it the change in water temperature?

It simple terms its the warm water sitting on top of cold water.

More in depth. I always used the above answer before I started diving. Here is how it really works. The top answer is still true. The water temp drops can be drastic also.

Most lakes will have the warm water sitting on the top of cold water. As you descend and hit the thermocline the warm/cold water mix and give a real hazy look almost like steam coming off hot wet pavement. The water usually clears as you decend through the thermocline and reach the bottom. Atleast this is my experience in diving alot of lakes.

For example one of my dives this weekend the first 10 ft were reasonably clear. Then at about 12-18 ft I couldnt see anything at all. When I hit 25 it cleared up almost as clear as when I was at less then 10ft. Not all lakes are like this but most clearer lakes I have dove all share this similarity. This dive the surface was 78 degrees. approx 15 ft was about 60 deg and 40ft was about 50degrees.

I'm sure this has been answered several times on this site.

For an in depth answer Google "thermocline in lakes".

The basics for bass fishing; warmer water is less dense than colder water, the zone where the warm and cold water come together is called the thermocline. The thermocline is usually a fast temperature change of 2 to 5 degrees within a few feet of depth.

The summer thermocline occurrs as water warms, the winter thermocline occurs as water cools. Current or wind can desperse the thermocline, calm conditions can increase the thermocline.

Bass during the summer period prefer to locate just above the thermocline depth.

You can see the thermocline on good sonar units as a darker color zone or line due to the water density change.

Tom

I've been hearing alot about thermocline. What is it? Is it the change in water temperature?

That was discussed in this thread, I posted some thermocline screen shots.

It's the "metalimnion", a narrow band of water exhibiting rapid temperature change

which is sandwiched between the epilimnion above and the hypolimnion below.

Roger

If you have versus, there was an episode of the bass pros that explained it perfectly. They put re runs on quite frequently so look out for it