When fishing for stripers and hybrids at Lake Hartwell in the summer, it is imperative to understand the thermocline in order to locate the fish, according to guide Preston Hardin of Commerce, Ga.

“Starting in June, the fish ride the thermocline heading south,” Hardin said. “By July, they are well on their transition to the lower lake. In early July, I might still be fishing no higher than mid-lake, but by late July, I will be fishing the lower end of the lake because the creeks and upper lake are pretty void of fish by then.”

It all has to do with the phenomenon known as the thermocline, he said. That’s the layer of water between the warming water in the top of the water column and the cooler water towards the bottom. As summer progresses and the surface water heats up, the thermocline moves deeper, eventually pushing the fish out of shallower creeks and coves into the deeper water in the river channel and down the lake.

They seek the comfort of the deeper water, which is cooler, but they also have to stay at depths where the dissolved oxygen content is enough to sustain life. If you drop a live herring down and it is dead when you retrieve it, you probably are fishing too deep, said Hardin (706-255-5622).

“I will be fishing at least 30 feet deep by July,” he said. “By then, it’s mostly down-line fishing and the fish will be grouped up in pretty big schools, about 50/50 stripers and hybrids. You can get on them and catch one fish after the other. If you find the fish and put a blueback herring near one, he is going to eat it.”

The key, he said, is reading your depth finder, because there will be very little surface activity as the fish will be holding in deeper water.

“You are looking for groups of fish, and you want to look in open water. Usually, they are not really deep in July, maybe 30 to 60 feet deep, but by August I will catch them at 120 feet deep,” Hardin said. 

The good thing, he said, is that by this time, the fish have begun to school by size, so he can keep away from smaller fish and target larger ones.

In July, the top tactic is dropping live blueback herring down into the schools of fish, Hardin said, but there are also two other ways he likes to fish this time of year.

“Instead of casting a Fluke on a jighead, we go to a big, 1-ounce jighead with a swimbait and working it vertically, not so much jigging it as reeling it up and down through the fish. I just like dropping a swimbait in the fish,” he said. “I used to power reel with a jigging spoon — and that works, too — but the most-effective way to catch these deep fish is to drop that live blueback herring down into them.”

And, while there is very little surface activity, Hardin keeps a Lucky Craft Sammy in ghost minnow pattern just in case.

“When it gets hot, I always have one ready. If a fish hits the top of the water, even if it has quit, I still throw it over there and walk the dog back,” he said.

Besides finding fish grouped up in big schools, making it easier to fill a limit, Hardin said there is one other benefit to fishing in mid-summer — there is plenty of time for breakfast before you have to get on the water.

“”By July, I don’t usually go out until 7 o’clock because you just don’t need to be out early. I like for the sun to get up and push the fish into the ditches,” he said.