I always preferred the northern part of the lake, and the Pilgrim's Cove area, but only because that is where our cabin was. They will certainly drop to 20' at times. We have caught more than one big mackinaw with a dinky little triple teaser while koke fishing. We often let one line just drop while fighting a koke on the other. Then, when we popped it in gear again, there was the mack. That's fun on light line and the smallest of lures!! Oh, to answer your question, they don't get that big. The average over many years was probably 10-12". Mike