Owner #1 (We are #3) must have been an amateur submarine hunter because under a well made box in the v-ee berth I found this. Its a "Wesmar" sonar. The company is still in existence http://www.wesmar.com/ , wonder if they want this for their museum;
It is bolted on to a massive flange glassed in to the bow and can be lowered and raised. Well its about to be removed and replaced with a more manageable sized depth transducer..