I have found that if I set my side image range to 40' and no more than 60' on each side that I am able to see fish better on my HB 899 unit. Look for the rice grain slivers with shadows showing off to the side on the bottom of lake. This is fish some what off the bottom of the lake water column. The more you use your unit the more you will learn what you are seeing on it. Remember tho that the further the range the smaller the images will be especially on the smaller screen units. You are right good structure is always a good place to look for fish but with a little practice with your new Helix 7 SI you will be able to find and see fish on this structure. Hope this will be a help to you I am just learning all this myself. Good luck with your new unit and I will be looking forward to seeing your fish and sonar pictures.