I'm getting ready to install an XM 9 HW MSI T transducer on my boat, and I'm thinking of putting it down at the bottom of the transom so it skims the water at high speed. That would allow me to avoid installing an in-hull transducer for depth readings at speed. I know that increases the risk of the transducer getting damaged from striking objects. Aside from that, is there any other reason not to do this? Are these big SI transducers meant to be able to skim the water and give depth readings at 50 mph?
Another question I have is about distance from the prop. The manual says it should be at least 15" to the side of the prop. My boat has a stepped hull, and the easiest mounting location for the transducer might be in front of the prop, where it would still be more than 15" away. Would that work, or does it really need to be off to the side?