My brother and fishing partner recently purchased a used boat that included a HB 997c. We both are experiencing SI for the first time and thought the images, although viewable, would have more clarity. They all seemed a little blurry and fuzzy. All updates were downloaded and settings recommended by Doug V duplicated. Maybe we overestimated how vivid the images would be. Is there anyway to reliably test a unit to verify that it is producing screen images with the clarity it should? Any help would be greatly appreciated.