Thanks for all the responses already (that ws quick!). I think I get
the idea as to where to mount it which brings me to my next question:

I am a bit freaked out about putting screws in the transom below the
water line. Is it possible to attach (with screws) the transducer to a
hard plastic (like a thin cutting board as someone suggested) and then
use above water/below water marine clue to secure it to the transom?
Or am I just suffering from unjustified paranoia (hey! it is a brand
new 2006 boat so not keen about putting holes in it!).

Andre