[CA] [CA11] dragonfly 5 transducer info

[mtnbowhunter]

I spent several months in Baja using the D5 in saltwater on my aluminum hulled inflatable. the supplied transom mounted transducer worked great at low trolling speeds but when trolling at 5mph and above it increasing develops lack of definition or "snow", and once at planning speed it completely blacks out. I presume from propwash. numerous repositioning of the transducer did little to help the problem.
so my questions are :
- should a thru hull transducer cure this problem?
- which transducers will work fully with the D5?
- the hull is a shallow - 10Degree or so - v, no steps, so how does one install the thru hull so it is parallel to the water surface?
- will testing the location of the transducer in the water filled bag work in an aluminum hull?
- I believe, according to westmarine, that one of the dragonfly compatable transducers that had a plastic body, has been discontinued?Why???