The Humminbird 571 HD DI Portable is one of the latest models in the Humminbird 500 series. So far, it's one of the best monochrome units with Down Imaging that you can have. It features a 5-inch diagonal, 16 LvL Grayscale screen, 640X320 pixel resolution. Even though it's black and white, it provides excellent, crystal-clear images, with very little noise, making it very … [Read more...] about Hummingbird Fish Finder 571 HD DI Portable Review