Here are two more screen shoots that i did from a recording from my Humminbird Onix 10 SI Cross Touch unit. As you can see from the first screen shot there is a school of bait fish and to the right there is a small top or stump. Can you spot the top and the possible fish in that area?
Humminbird unit down image set to 455 kHz settings.
Down image set to 800 kHz setting.
Now let’s look at another screen shoot from the same area but this time I have the 800 kHz settings instead of the 455 kHz. Can you see the treetop and or stumps from the first screenshot? As you can see there is a huge difference when you are looking for structure and fish while scanning with your down image unit.