I have one big ***** about my new garmin 240 blue. No actually several. Do not expect this unit to show any fish as arches. Do expect to see schools of bait marked as large columns of fish. Thermalclines will also show as fish. I have never spent so much time fiddling and adjusting and dialing in a fish finder in my whole life! Never have gotten any concrete feedback/answers on adjustments. If anyone else can absolutely tell me what is going on, I would like to hear thm speak up. Not what I expected for the money.