This is another Humminbird unit that provides the basic fish finding features, plus Down Imaging. The Humminbird 571 HD DI is a monochrome unit, with quite a wide screen, 5-inch in diagonal, 640 x 320 pixel resolution 16 LvL greyscale. It's an HD unit, delivering images of higher accuracy, in SwitchFire and Down Imaging. It's sonar capabilities are similar to the ones of … [Read more...] about Hummingbird Fish Finder 571 HD DI Review