Btw, are you running another unit on your boat? If you are running two depth finders, you need to run them at different khz. For example, the front on 200 khz, then the back on 83 khz.If you run both at the same time say both at 200 khz, you will get interference because the signals will bounce off each other. Trust me, I know this is a fact. I have talked to a Lowrance rep in person about this.