I have a Humminbird 998 si on my trolling motor . It seems I dont get enought fish symbols I never get arches should I get arches on bird or is this just a lowrance thing. I have the senitive set at 13 what should I set it on 83 hz or 200 ? Also my new boat came with a lowrance X5 in the dash on the right i have a bird 1197si . If I turn both on at the same time on the lowrance I will get fish arches on the bird I will get lines both trans ducers are mounted on back of boat I have the bird interferance set on High 1 . I am finding a lot of fish supended on the front of deep docks 16 foot or more. On bird sidefind they are stright lines but no fish symbols or arches on 2 D why is this ? Thank You