I posted this about 3 years ago but didn't get much response so I thought I'd try here again. Bought the HDI-5 Elite HDI and am a novice to setups. It's mounted on back of 1 pontoon where the airator pump box is but sticks below the pontoon. Cannot for the life of me get fish arches on the sonar. Can sometime get bait fish on downscan but not much there either. I fish fresh water in 50 ft maximum but usually under bridge or in cove of abount 25-30 ft. Really would like to use it to identify schools while under way and I need someone to give me the optimal settings to make this thing work right. 1st Lorance and bought it due to reputation. Previous 99.00 hummingbirds and somewhat same problem. Was hoping stepping up a couple grades would make a difference. All the videos I found on line were real short how to set this thing so it would work.

Maybe your problem is not knowing how fish arches are created. This will explain it:

http://saba.kntu.ac.ir/eecd/ecourses/ins.../fisharches.htm

Thanks, I'll try adjusting some more stuff