Hi guys, I did the fix on this depth sounder described on youtube it worked ok for a while but it's playing up again so it's time to move on. I'm look at a cheap fish finder/depth sounder from BCF as the Navman is no longer suported.

It appears no mater how I go I will have to haul out to fit a transducer unless I can get something that will run on the existing transducer.

Any thoughts on the above?

Bill

I belive, the transducer is manufactured to specific frequency and the transmitter is tuned to it.
You can try, might by lucky.
Cheap sounders usually have transom transducers.

Garmin website:
Will not work on a boat with an inboard engine due to the turbulence forward of the sensor
Not recommended for sailboats because of excessive heeling
Will not work on stepped hull.

long time ago, I use large dia plastic pipe, fill up with oil, remember working perfectly.
/ of course pipe was laminated to inside hull and transducer was properly positioned and attached,
oil filling hole permanently closed/

I got a Navman 3100 system on my boat, and last year I thought, it was playing up for a while until I read the manual how to operate it. The transducer - luckily - was fine, l had problem with the boat speed reading and a damaged impeller. I was looking for replacements and researched the project. It has a thorough-the-hull transducer in a certain diameter - I can not remember what size (1 3/4'???) - but I remember, no other brand had the same diameter transducer. All were larger by .25 or.5 inches. That ment a lift-out and drilling, fitting etc. So no good news here.
I would not trust a siliconed-in transducer anyway.

While researching the subject l found a gold mine of parts for Navman. It is Boat Harbour Marine Scarborough Qld. The proprietor is Fletch. The phone number is 0413-691614 he is a good chandler thou cantankerous and he does refunds correctly. I dealt with him for months while l was up there. He had a !!brand new transducer!! in stock.

Whoever, l am looking for a Navman display, l am even advertising on Buy&Sell about it. If you decide to replace yours, would l have the ghost of a chance to buy the display of you? Send me a pm.
I hope you manage to solve the problem. Sometimes the wiring is pinched and damaged, connections loose it might be worth investigating this before you junk it.

Yes, true it's history BUT at a glance you can see the trend. Is it getting deeper or shallower. If you dont have a bottom profile display, you have to keep the digits in your head for the next time you can afford that glance down to your instruments.
Only my opinion, but as a hydrographic surveyor who has spent many hours hunched over a rolling paper sounder display, as his boat driver tries to keep the vessel on line and on the back of a wave if heading towards a shoal adjacent to a barway. The driver has enough on his plate to keep the boat safe without having to stare at a sounder to determine the current depth trend. It's the sounder operator who calls abort when he sees the bottom gradient trending to a dead end.
And besides all that you find the fishfinder is generally cheaper and outputs NMEA depth if you wish to record your passages or survey an anchorage. You can also see what the bottom is before you anchor with a fishfinder. Weed, rock, sand and mud show up very well.
As do fish if you want to turn the fish symbols on for a feed of flathead or whatever.