Matt & Michelle Day, SM#208 SV Talia
I cannot speak to your hull number (we need Bill's expertise). We are hull number 209.
The AMEL installed transducer at the fwd head is 38mm diameter. The new transducer (DST810 and DX900) is 51mm diameter. I refuse to leave the old thru hull, so I will oversize the exiting for the new install.