I have a 17' lowe aluminum bass boat and I always seem to lose my bottom signal anywhere from half to full throttle. MY boat only tops out at about 35mph, what could i do to try and prevent that from happening? The transducer is set up as per installation instructions, making sure a line of rivets, or rakes or anything are not in the way. Should i try and drop it lower than the bottom of the boat rather than not even?