Why Are They Deep
Sometimes the Smallmouth Bass just disappear. You can spend hours casting over the rocky shoals, river mouths or rocky points and catch nothing. Many times the reason you are not catching anything is because the bass have gone deep.
My experiences of fishing deep for Smallmouth have been on Lake Erie or in Algonquin Park. After hours of catching nothing, we turn on our depth finder and try to find a deep ridge where the main drop-off starts at about 35 to 40 feet deep.
There are two main reasons why the Smallmouth Bass go deep. The first may be because the population of Smallmouth Bass is so high that they have eaten the shore and shoals clean and have to go out into deep open water to feed on Lake Herring, Chub & Suckers. In early spring and late fall when the weather is unstable bass tend to go deeper to minimize discomfort because of drastic changes in atmospheric pressure. In Ontario July, August and the first two weeks of September is usually the best time for Smallmouth Bass fishing as the bass are usually up on the rocks in their normal feeding patterns.
Smallmouth Bass go down deep to feed on baitfish, which like to hang around deep ridges for protection. The bass also go deep when the weather becomes unpredictable. Unpredictable weather brings sudden changes in atmospheric pressure, which in turn means fish can feel a lot of discomfort in shallow water. The bass go deep to minimize this discomfort. When they go deep, they hang around drop-offs or underwater ridges so they can quickly swim deeper or shallower as the pressure fluctuates.
On Lake Erie, we drift over deep ridges with worm colored tube jigs. We even shove a piece of real worm inside the tube jig just as an added boost. The action we seem to do best with is one long jig (5 feet up) and as the jig sinks, give it little tiny jigs to give it an agitated motion as it sinks. You can let the tube jig spiral down naturally, which works, but not as well as quick jerks which makes the tube jig look like an injured fish or bug. Another reason why we give it little jigs as it's sinking is we can feel the bass hit the jig. If it's really calm water, you can see that your line stops sinking, which could mean a bass has hit the jig. If there are waves, it's best to feel the fish bite with your fingertips.
In smaller Canadian Shield Lakes like they have in Northern Ontario, we find the best way to get the Smallmouth is to get a big worm on a bass hook with no weight and just let the worm slowly sink down to the ridge. If you are drifting over the ridge, just give it a jig towards you about 2 or 3 feet and then let the worm sink again. When the bass hits the worm, unclip your bail and let the bass swim with the worm for a few seconds. Tube jigs do work in the smaller lakes but not nearly as well as real worms. Dropping a minnow straight down also works well but many of the lakes in Ontario, especially in Provincial Parks, don't allow the use of live minnows for bait.
Smallmouth Bass & Walleye both go nuts over salted (salt cured) minnows. I just catch a bunch of minnows and throw them on the grass until they die and dry off a little. They get a large container, put a layer of salt, then a layer of minnows, salt, minnows, etc..etc... I use table salt or fine grain pickling salt. Don't use Rock Salt as it has chemical agents, which will keep fish away.