The thermocline of a lake generally dictates how deep bass will be during the summertime. As water gets warmer in late spring a lake starts to stratify with warmer water on the top layer of the water column and cooler water below.
The thermocline is the middle layer where the water temperature changes rapidly and fish tend to gather because the cooler bottom layer lacks dissolved oxygen. On clear lakes the thermocline tends to be deeper ranging from 20 to 40 feet deep. I have found thermoclines on murky lakes ranging from 8 to 15 feet deep.
My game plan for summertime bass fishing in clear or murky water is pretty simple. If the lake is clear I mainly concentrate on deep fish, but if the water is murky I head for the shallows.
When fishing for summertime bass on clear lakes, I target the main lake where I can fish deeper structure such as points, ledges, bluffs and channel swings. If I see bass suspended on my depth finder I will cast swimbaits to tempt them with a horizontal presentation or employ a vertical jigging presentation with slab spoons or a finesse worm on a drop-shot rig. When I see bass hugging the bottom on my graph, I try dragging a football jig or a Carolina-rigged soft plastic lure along the bottom. Some bass suspend under main lake boat docks where I catch them on finesse jigs and shaky head worms.
Clear lakes are also great for night fishing. On calm nights I favor working Texas-rigged 10-inch plastic worms or bulky creature baits through brush piles 20 to 30 feet deep. I switch to slow-rolling a black 3/4-ounce spinnerbait along bluffs on windy nights.
Summertime bass in murky lakes will stay in thin water if there is plenty of cover and forage in the shallows. The fish will also suspend higher in the water column under boat docks or in branches of standing timber. I use power fishing tactics such as flipping a jig or Texas-rigged creature bait or burning squarebill crankbaits into logs to catch shallow summertime bass.
I throw topwater baits around the docks and the standing timber in the mornings to catch bass suspended in the murky water. Swimming a Texas-rigged 10-inch plastic worm with a 3/16-ounce sinker through the branches of standing timber is an effective way to catch suspended bass later in the day.