I have the eagle fishmark 320 fishfinder and have installed it as it says to in the book.I cannot distinguish anything unless I have the fish ID on.The full screen is just pure clutter and no visible arches,When the fish id is put on,it shows fish,it is quite accurate as I have put it on over areas I know to be black with fish.
Is this normal? Is it just picking up silt and debris floating about in the under tow,or is it picking up the under tow its self?