One more thing Sonar Charts does, if you use the Navionics app in your phone, this just happened recently. There is now a WiFi sonar unit that will work with your phone and the Navionics app to give a sonar display right in the app on your phone. I was sent one to test and have been playing with it, the feature was just added to the Navionics app so more time fishing with it is required to say too much but it is pretty cool so far!!