Thanks Greg, anything past about 6-7 knots (8 MPH) isn't readable on my unit, so I'm guessing the transducer is far too high, I usually go pretty slow, 4 knots at a guess and troll two lures to find spots. I'm looking for large structure though, so I don't need perfect precision, and speed would help cover more ground. I'll definitely post the pics before I change the height and I'll post the results afterwards.
Thanks again.