Most aluminum boats seem to have this problem I have found. That transducer has to be PERFECT and have no air bubbles flowing across it. Which Is very hard on most boats if not impossible. Some may have dialed it in perfectly on their boats and achieve speeds 20+ MPH. But to me I feel like If you are getting to 10-15mph before you are loosing bottom....you aren't doing too bad. You can always experiment with moving the transducer around and try to improve your situation....just don't get discouraged if it doesn't get much better.