This video shows the very beginner basics of sonar frequency selection and how that selection translates to what you see or don't see under and around your boat. Again there are some very advanced units and technology, but this is just the very basic beginner level info for better understanding. This video demonstrates how the kHz selection will vary your transducer cone angles, how to determine how wide the diameter of your cone is viewing the underwater terrain and fish, and a brief description of using split frequency to your advantage. I hope you enjoy