Transducer location

[rigi36]

Needs to be parallel to the water and point straight down.

What do you do when the hull isn't straight like this?

[longjohn]

You do this:

[Ovey]

+1 That's about the same position mine is located.

Biffer fitted it for me, and it's not where I would have put it based on the manufacturer's fitting guidance, but it works perfectly at all speeds from 0-WOT!

[scubaqua]

Try first to put it in your bildge (if you have one). Works great. Only thing which does not works is the watertemp, because it's the bildge water which is measured...
No holes in the outside of the transom...