Since walleyes have excellent visual acuity under low illumination levels, they tend to feed more extensively at dawn and dusk, on cloudy or overcast days, and under choppy conditions when light penetration into the water column is disrupted. Although anglers interpret this as light avoidance, it is merely an expression of the walleyes' competitive advantage over their prey under those conditions. Similarly, in darkly stained or turbid waters, walleyes tend to feed throughout the day. In the spring and fall, walleyes are located near the shallower areas due to the spawning grounds, and they are most often located in shallower areas during higher winds due to the murkier, higher oxygenated water at around six feet deep. On calm spring days, walleyes are more often located at the deep side of the shoreline drop-off and around shore slopes around or deeper than 10 feet.