When most of us think about the thermocline, we think of a deep layer of water below which there’s little or no oxygen and even less fish activity. In my experience, that’s only partly true. There may not be very many fish below the thermocline, but it’s not always deep. In fact, it can be quite shallow at times.
I’ve often found what I believe to be a thermocline in about 3 feet of water below heavy lily pads and vegetation. The total water depth might be 5 feet. The bass seem to hold right above it — maybe around 2 1/2 feet. This formula generally holds true around other kinds of structure and cover as well. Sometimes you’ll find good bass holding at 4 1/2 feet around docks when the thermocline is at 5 feet and the total water depth is no more than 10 feet.
The truth is that I don’t have any solid scientific evidence to support my theory that thermoclines can be as shallow as I’m suggesting. Nevertheless, years on the water have convinced me I’m onto something.
Some guys have told me that all I’m doing is finding bass that are holding right above the bottom or suspended in some way. That could be true, but it doesn’t make sense to me that they are doing that all over the lake, around all sorts of man-made and natural structure and cover.
Check it out for yourself. Set the sensitivity up on your electronics and cruise some of the areas I’ve talked about. You’ll see that all-important gray band across the screen. It’ll be surprisingly shallow, and in surprisingly shallow water, too.
I’m convinced that a lot of anglers don’t know about shallow thermoclines because they aren’t looking for them. I know that was my problem at first. Once you find a couple of them, however, you’ll become a believer in no time at all.
My favorite, and most effective, way to target these fish is with a Texas-rigged white plastic bait or jig with a white skirt and trailer. My presentations are always vertical. I cast or pitch my lure out, let it fall straight down — perfectly straight — and watch for the telltale twitch of my line. If I don’t get a bite, I reel back in and do it again somewhere else.
I never hop or swim my lure. It’s straight down and then right back for another vertical presentation. The bass are either there and active or they aren’t. There doesn’t seem to be any in-between.
Sometimes when you encounter a shallow thermocline there will be a topwater bite as well as a vertical bite. When that happens, I throw a white frog. These fish are active fish, so I keep my frog moving. A more subtle approach doesn’t seem to be all that effective.
The reason I go with white during the hot summer period is that most bass are feeding on shad. White seems to be a color that matches them perfectly. I also think there’s another factor at work with white. They don’t see it very often. White gets their attention. It’s just not all that popular with bass anglers.
You may have noticed that I haven’t mentioned any specific baits. That’s because this is not a product- or bait-specific technique. I use several different plastics ranging from big creature baits down to small grubs. My jigs are all ordinary. You can buy them in any tackle shop. Tie on whatever frog suits your fancy.
Some of you may not agree with my thermocline thoughts. That’s OK. It works for me, though. What would it hurt to give it a try? You know what they say: Don’t knock it 'til you’ve tried it.