A New Fish Finder / Depth Sounder and Getting Very Lucky on eBay

Rosalind underwent a significant refurbishment in 1997 by previous owners. The work included a new Raymarine fish finder/depth sounder and a custom varnished teak box at the helm to house the display unit. 

On our way back from our Saint Michaels shakedown cruise, as we were about to enter the West River where Rosalind is moored and almost 30 years after it was installed, the display of the combined fish finder/depth sounder stopped working. 

30 year old (non-functioning) fish finder/depth sounder 
Teak housing box (with large hole) and wiring in background

We were now faced with a challenge. Get a new unit or try to find a replacement for the 30 year old unit.

Installing a new unit would require a lot of work. We would need a new through-hull transducer, new wiring, and a new way to mount the new display in the old teak box. To install the new transducer would also most likely involve some fiberglassing as the transducers are not all the same size. Also, if we opted for a new one, the work would have to wait until Rosalind was out of the water, and we would not be able to test the unit until next spring. 

The second option was to go hunting and see if we could find a replacement for our 30 year old unit. We figured that this was the place to start. Our hypothesis was that it was the display and not the transducer that went bad.  If we could find a replacement unit that worked with the existing transducer, then we had a chance of saving many days of work. But we would be looking for a 30 year old unit! 

It took a little bit of work to figure out how to remove the old display (it was glued in place). With the old unit out, we examined the electrical and transducer connections and figured out what we had. Then we went to work and within an hour we hit the jackpot:  a brand new (in the box) 30 year old unit with a transom transducer. We assumed that the two transducers (transom vs. through-hull) were interchangeable as far as the display was concerned, crossed our fingers, and ordered the unit. 

The box arrived, and as advertised, everything was brand new! We were holding a 30 year old time capsule. A few days later, we tested the new display with the old transducer and presto, we are now back in business! What luck!

Here are a couple of  pictures of the new unit.

The brand new unit, all original and 30 years old!

New display installed - We got so lucky!!