Another thing to do is adjust your transducer angle on the back of the boat to compensate for the blowback. I used Humminbird 500 and 700 series with good success but recently switched to raymarine c-series and would never switch back. it is all personal preference as they (lowrance,raymarine,huuminbird,furuno, etc) will work. I know i had to to do alot of tweaking to get my humminbird where i wanted it but when i did it was good and i could track them down to 100' or so.