I want to thank each and every one of you who has taken the time to answer my question.

I would also like to apologize to the original poster for hi-jacking their thread. SORRY!!

I contacted Airmar and they were helpful in answering my questions. They stated that if you are running an inboard then a thru the hull transducer would be the best choice if not the only choice. They stated the prop wash would interfere with the transducers ability to send and receive the return signal if it were a transom mounted transducer.

If one is running an I/O or an Outboard then the transom mounted unit will work as well as the thru the hull model so long as it is installed right.
So I believe I am going to go with the Transom mounted transducer.