I have 797SI and It is mounted in the rear. I know you are having problems with to motor in the way but you might be loosing out if you do it you way. I can mark the leaves on the surface with mine. I f you have ribs on the bottom of your boat they can block it also. I am just saying the it may be better to tilt the motor up a little to clear it. You drill that hole and it is there and that will cost to repair if it don't work. Another thing I beleive those are made for larger boats of fiberglass and wood. I know aluminum flexs when hitting wave. I may not break off but could crack the epoxy resin and sealent and start leaking. Hate drilling any hole in a boat. Eric