Some people have been asking me to put this up so here goes

After purchasing the new fibreglass hull i was back sourcing the best low budget, best performance sounder set up that was able to perform in depths upto 700 meters.

Starting with conversations with taylor marine in the west and in the east i had heard the Furuno 585 unit boasted excellent performance for game fishermen in deep water. The best results were coming from thru hull instalations using the 50b-9b Transducer.

Having the same sounder system from my old vessel the next step was to liase with cruise craft on hull construction and if it was possible to install the transducer where i wanted it at the stern.

With a flat surface on the keel line this install was quite simple.  

Then was to cut thru a moulded bilge liner and having a very restricted area to work in.

Next was by far the hardest. This was actually getting the nerve to cut a 160mm by 90mm oval  hole through the hull.

With that done you realize your in so deep you had better do the rest right if your ever going to go boating agian!!

Then i made an exact replica of the transducer but 3 mm larger all round.

The replica transducer was now waxed and release agent applied.

Then the replica was inserted in the vessels cut hole, flush on the front edge and 2mm lower of the rear edge so that no air pockets could ever occur under the transducer.

From there work began on the inside with me applying epoxy fibreglass matt over the replica transducer and onto the prepared inside hull with a 100mm overlap onto the hull.  Four layers of 400 chop strand mat was applied then left to cure.

When cured the replica plug was pushed out by drilling a small hole in the center and tapping out. A larger hole was now drilled in the center of the formed fibreglass housing to suit the transducer cable and the inside of the housing sanded and cleaned with acetone.  

With the housing ready for the transducer. Marine Sikaflax was applied inside the housing and on the transducer. The transducer was now pushed slowly into place and secured, letting the air bubbles escape.

The excess sika was wiped away and another 4 layers of glass applied.

Now all that was left was a quick sand and for the white flow coat to be applied , bilge pump fitted and any sika marks to be removed with acetone.

All done and left to set.

On trial the new picture was almost unrecognizable from the memory of the ground when the transducer was last transom mounted on the previous vessel! A huge improvement. And where before we were sounding in the 250's to 400's at less than 5 knots, now we were clearly seeing ground at 10knots and breaking at 15.

The last shot shows us sounding at 840meters. Faint but readable.

Anyways hope this comes to some for benifit.

BTW this is no plug for furuno. I couldnt care if it was an Nintendo.  

I also believe similar results could be achieved with other sounder systems but the wet transducer face system (through hull) is crucial.

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