Knowing the habits of various species is also vital. Shad, for example, generally appear as a large mass, and walleyes usually appear as a group of individual makes related to the structure. Knowing which bottom types hold fish, and how to find them, is also extremely important. If a second echo appears on your sonar screen, for example, a hard bottom is directly below the boat. If the double echo disappears completely, the bottom is most likely soft.
Walleyes usually prefer harder bottoms.
I ve discoverd that walleyes on deep water humps or submerged reefs are usually easier to find and catch then shallow water fish. I ve caught some large walleyes fishing these submerged humps in 35 feet of water. By in large, hot weather patterns include brushpiles or weeds on humps in 15 to 20 feet of water, and creek channels lying at the same depth. Inside turns on these humps or boulder edges are also prime locations. The best way to fish these underwater structures is with a live bait presentation.