One important function of cover is to provide shade. When can we expect bass to seek it? Anglers intuitively assume that fish experience changes in daylight as humans do. We presume light underwater is dimmer at dawn and dusk than at midday, and label dawn and dusk the low-light periods.

Before sunrise and after sunset, the amount of available light is low, but once direct sunlight hits the water, almost as much underwater light is available in the early morning and evening as at noon. Because water molecules, suspended particles, and plankton in the water scatter light in all directions, there’s almost as much light in the depths shortly after sunrise as later in the day.