A very good in depth look at why fish show up as arches on our fish finder screens. Many times we look at our fish finder screens without 100% knowledge of what it is we are looking at, and wonder why we are not seeing or catching more fish. I know lots of people who have spent thousands for big fancy sonar units, just to use them as expensive depth indicators. I have challenged myself and others to really dig in and learn as much about our electronics as possible to help us become better anglers.