Quote Originally Posted by GreenHead View Post
Done the adjust up-down and tip it down a little bit thing. Transducer is located between the two hull ridges. If I move down and center between the next two, I would be pretty close 9" from center back edge of lower unit. Does Rotating circumference of prop have any effect on them when you get to close? My hull is riveted aluminum and lots of them as well.
My very next question was gonna be is your boat aluminum riveted. The rivets trap air behind them and then release as you move through the water. The bubbles cause the interference. Try and place the transducer between the rows of rivets.