Ok the sensitivity u have to adjust on the water,if u fish inbetween 4m to 20m adjust the sensitivity up so its like snow, than adjust it back til all the snow on ur screen is almost gone and thts it all done, after u set tht up if u fish under 4m it wil come like snow again need to adjust it back more, if u fish over 20m need to adjust it forward cause u wont see no fish it wil be just very clear, im no expert iv had 3 of these sounders over the years it seems to wrk 4 me, also i only see fish with the sounder page not the downscan page, i use the downscan page to look at reefs and the traditional sounder to find fish, u can use both screens at same time which makes it easy