I've been trying to see fish under docks with my Helix 10 mega image. I am not having any luck. My sensitivity and contrast are set up well enough to make schools of shad pop out but seeing fish under a dock is a whole different matter. In about 8 to 15 feet of water I will run my range out about 40 feet but all I see are tiny thin images and shadows of the pier pilings. If the pilings look that tiny how in the world can you see fish?