The Lowrance 5xdsi ONLY has down Imaging were the humminbird 596c HD DI has both the down imaging and sonar + some and for the same money http://store.humminbird.com/products...be2fab632e9a98

I was going to get the lowrance until the dude @ bass pro told me the difference. I'm very pleased with the unit and have already caught a lot of fish with it..