Most of us overestimate how large of diameter the cone actually is. If you are using a 20 degree wide angle cone on the TM you can pretty much divide the depth of the water by 3 and come up with the approximate diameter of the circle you are able to see objects on the graph.
So in 24 feet of water you can roughly see an 8' radius directly under the transducer. Thats not very big. If your bait is more than 4' off to either side of that, you ain't gonna see it bud and thats if your bait is near the bottom.