Re: "it's much better to use the correct thru hull ducer,along with a fairing block cut at the correct angle,or to properly install a transom mounted 'ducer-afterall,that's what they were designed for..."

First...per my previous post.."but the solution that best meets the conditions (performance, time available, cost, quality, resources...etc) that the problem presents."

1) I don't like to drill un-necessary holes in my hull. And I'd hardly call "shooting thru the hull" as something that the transducer wasn't designed for since the installation instruction with my transducer indicated that doing that was acceptable...and the transducer supplied was not a thru hull.
2) Mounting it on the transom... OK that's what I originally wanted to do.. but then again READING THE MANUFACTURERS INSTRUCTIONS I realised that there wasn't enough room on the transom to do that due to the trim tabs.

Sooo.... back to shooting thru the hull. Given the location of the external wedge water strainer on the hull I wasn't sure that the location that I'd picked would not be a problem due to the nearby strainer so I wanted a way that was "not permanent".

Also... since my wife gave me the sonar as a Father's Day gift and the boat was in the water already where it lives 7 months of the year, I did not want to pay to have the boat hauled... which I would have to do for EITHER method you insist are the only right ways to do it.

As I said... "but the solution that best meets the conditions (performance, time available, cost, quality, resources...etc) that the problem presents."

Furthermore I take exception to your snide and totally unfounded attacks on my engineering ability.

The reason I'm not working as an engineer is two fold.
a) They exported my job overseas.
b) I worked in the Whippany area and live in Island Heights.
The 4 hr per day commute and the 10 hrs/day work day and the high stress were taking a toll on my health...

As to how good I was as an engineer... I worked for almost 20 years as a consultant at Bell Labs and Lucent and for one of the Lucent spin-offs. I was not the typical (get hired and write 20000 lines of code and leave programmer)consultants... I got hired by and large to bail Bell Labs and Lucent out of problems. I have two high tech patents and had two others pending.

BTW... My boat has a MERC engine in front of a VOLVO drive.
Something that you think is somehow "improper"... Again.. you don't understand the problem to be solved.

Volvo drive ChrisCraft Lancers have an unusual setup. While they use a sterndrive, they do not PER CHRIS CRAFT REQUIREMENTS use a sterndrive engine. They have a special intermediate housing (elongated) that takes an INBOARD, i.e., bobtail engine. Hence the 5.7L MIE engine. Why MERC... A friend of mine was badly screwed by VOLVO on a warranty issue, so I took my business elsewhere. The last time I re-engined a 1969 Lancer (not this hull) I installed a 318 Chrysler... A bobtail engine is a bobtail engine.

Also...re:"i'm sure you can spend your time "reinventing the wheel"... Actually not so much "inventing the wheel", but improving it. I was a hardware and systems development engineer.
Always looking for better ways to do things. I didn't make "the big bucks" listening to someone telling me what the "only way " was to do something.

You may a very good at what you do... Don't make the assumption that there aren't others out there who aren't as good or better than you are at what they do.