Ice,
I recently installed my 898 transducer on a Skeeter 16.5 footer with a smaller transom than most big rigs.
when I got my 898 I had no idea where or how to mount my SI transducer.
I did some research and found the Sternmate transducer mounting system.
I didn't want to drill holes in the transom, and the Sternmate uses an Epoxy which can be removed without damaging the finish.
I called the 800 number on the website and spoke to Capt. Chris
He asked me to send him some pictures of my transom, I did, he called me back, and we both went over the best location we thought the SI transducer would work.
I had to make install decisions based on our conversation, but the ducer is installed and working great!!.
I don't work for sternmate or related to the folks or anything like that, It's a great product and they offer great advice, I say give them a call.
www.sternmate.comgood luck