Are Your Old Autohelm TriData Electronics Extinct? Think Again!

Don’t discard your old Autohelm ST 50Plus Tridata system when it stops functioning!  First do the research and see if you can replace components that will bring it back to life!   For a mere $265, we’ve revitalized our system, but it took a bit of research and putting pieces of the puzzle together.

When we bought Winterlude, we had a great display of 3 year old instrument electronics – wind, speed, depth, all Autohelm ST50 Plus Tridata.  Now 12 years and 11,000 miles under the keel later, the instruments are beginning to die one by one.  However, a quick check of the pricing to replace them all with new Raymarine ST60 Plus Tridata gave us sticker shock.

So when our Wind Speed instrument stopped working last winter, we replaced the transducer at the top of the mast with a Raymarine ST 60 wind transducer that everyone told us wouldn’t work.  But the reality is that it does work, the wind speed may not be quite correct, but it gives us a fairly good approximation as well as wind direction.  Bottom line, for literally nothing since a friend gave us the transducer – it was part of a lightning strike and he had all new electronics and didn’t need it anymore.   He wasn’t positive it worked, but voila, problem solved. Cost $0

Fast forward to crossing to the Bahamas last year when the depth sounder decided to fail as we entered the harbor at Bimini to check in – luckily it waited until we got to the dock.  It was blinking crazy numbers when we knew we were in 7 feet of water.  Click here for the post covering the fun.

So we jerry-rigged the extra Garmin GPSMap 541S depth transducer that we just happened aboard and sailed the rest of the winter’s cruise to the Bahamas with two temperamental depth sounders that worked when they wanted and quit when they didn’t feel like providing information anymore.   Not optimum, but we made it and had a great time rather than running back to the US to get it fixed and losing our winter’s months cruising.

Since we couldn’t find a serial number on the depth transducer, Gemeco was able to identify it as an extinct P-19 from e-mailing this photo!

Prominent on our haul out list this fall was replacing the depth sounder.  In talking to Raymarine (Raymarine bought Autohelm) at the Annapolis Boat Show, they recommended we contact a company named Gemeco that apparently manufacturers all the transducers for alot of manufacturers and would be able to tell us exactly what extinct model we had and exactly which new model would work with it — apparently despite physically looking the same, different models run on different hertz’s and won’t talk to each other.

We contacted Gemeco and despite an initial mix-up with sending us the speed sensor transducer rather than the depth sensor transducer, they were able to identify which old depth transducer we had — a model P-19 and specify that the new 200 hertz transducer would be a model D800P-200-2.

In the meantime, we were trying to decide if we keep the incorrectly shipped speed sensor or send it back…

It occurs to us that in the last two years, two of the transducers have failed and both have been out of production and extinct.  There’s only one more transducer to fail, and it’s the speed version.  David checked it the new one sent by Gemeco by connecting it directly to the instrument at the helm and it works fine.  Then he checked to see that it fit inside our existing housing and found that worked fine too.  So now the only question is do we re-run the new wiring or do we simply splice the old wiring to the new transducer since we know the wiring for now is funtional.


Here’s the hole where the depth transducer came out — we pounded it out from above – this extinct style didn’t have the flange that it simply screwed into.  But look at that 1 1/4″ thick fiberglass!  No wonder this boat makes me feel safe and handles so well in rougher conditions!  🙂

So the moral to our story is that for $125 for the replacement speed transducer and $140 for the new depth transducer, Gemeco has solved our problem and allowed us to continue to use our extinct Autohelm ST50 Plus Tridata instrumentation!   WOOHOO! And thanks to our friend’s generosity with last winter’s wind sensor transducer, we have invested a total of $265 and have “new” functional instuments – wind, depth and speed!   Sure beats buying a new system for over $1,600.   Now if only the Icom M802 SSB repair estimate comes back at a reasonable cost!  Keep your fingers crossed!

I wish all boat issues were that easily (and inexpensively) resolved!

Here’s Gemeco’s contact information … anyone that answers the phone can help you — and it IS answered usually on the first ring by a real human being!  Customer service is NOT dead in America after all!

Click here for the follow up – after we received the new depth transducer and installed it — then splashed the boat and ….  Here’s the next post!   🙂

Gemeco – located in South Carolina — 803-693-0777 or e-mail

Do you have other ways to save extinct electronics/instruments?  Please leave a comment and share for all us good old boat owners that can always use help with these things!   🙂    Cheers — Jan



  1. Hi Jan, I have almost identical questions. I already replaced my depth headend and the transducer worked. I now have to replace the masthead windspeed transducer. I had the old Autohelm ST50 and now have a new Raymarine ST60+. Did your new windspeed transducer fit in the old base that is attached to the masthead? So just untwist the old arm and put the new arm into the base and done! Would you email direct at smdninefive@hotmail? replace the words ninefive with the numbers 95 and add .com to the end, in case any web bots try to hijack my email ID.


    • Hi Scott — check your e-mail! Bottom line is I snapped out the old ST50 wind transducer, snapped in the ST60+ and it worked. Raymarine tech support told us it might show 25% + or – difference in “real” windspeed. But we checked it with the boat across the dock that had an ST60+ and our speed was within a half knot or knot of his, so we’re not too worried. 🙂 I hope it works for you! Cheers — Jan

      • Pierre Aubineau says:


        I had the same problem with a ST50 wind display and the replacement of the transducer. The ST60 transducer works perfectly but it gives 20/25% more windspeed than the ST50 with no mean to correct this difference.
        I thus conceived a (relatively) simple electronic device which allows a precise correction when pluged between the masthead ST60 transducer and the ST50 display (in place of the Raymarine connection box). It cost me about 50 USD plus some work for welding the elements.
        If you (or other friends) are interested by this device, I can post you the schematics and the drawing which allows you to order for a small PCB onto which you have just to place the electronic elements (available at various Internet shops).



        • Hi, I would like the schematic for this device as I don’t have an ST50 compatible mast head unit.

          • Hi John! Unfortunately I don’t have a schematic — try googling it, I often find exploded diagrams of boat stuff by googling the topic. Sorry. Jan

        • Hi
          I’m based in UK and I recondition / sell spares for ST50 Wind Vanes
          ST60+ wind vanes do work with ST50 but will over read by 25%

          I also have lots of spares for Autohelm ST50

          • Hi Paul. I see you have spares for st50. I would like to talk to you.

          • Johnny Ross says:

            Just saw your comments on working on ST50 wind transducers. I have one that I need rebuilt, estimate please. The other question I have concerns the ST60 Tridata head. Can you repair it- or do you know someone who can. I have one of the earlier ones that I have replaced the transducers, but the head still does not have a display.
            Johnny Ross

        • Pierre Aubineau
          I’m interested in your wind speed correction device

          • Pierre Aubineau says:

            Hi Paul,

            I am now on my boat in Greece with poor Internet connection.
            I will send you all infos when I come back home in france.


        • Ciao Pierre, posso avere gli schemi di modifica del trasduttore testa d’albero ST60 per display ST50? Grazie

  2. Hi Jan,
    We met in Guatemala years ago,S/V Thalia now S/V Rendezvous,thanks for putting this very helpful advice out
    Peter ( widower)

    • Hi Peter! David & I are SO sorry to hear this news. We remember s/v Thalia well! Glad was helpful. Where is s/v Rendezvous? Great Lakes or ???? Cheers! Jan & David

  3. LOL… I started to tell you about getting the burned in, discolored faceplate replaced by contacting Carolyn Shearlock and Bam… realized this is Jan. I used to live in Burnt Store in 2013, 14 and 15. We were neighbors. Small world.
    I’m replacing some of mine and was reading your post for tips.
    I know it’s more work but I would run the wire from the tranducer instead of splicing it and then possibly having to splice it again, but that’s because the ABYC electrician said to never splice a transducer cable.


  1. […] a fish bigger than he was amused me for some time as I sat up there waiting for David to fix the old Autohelm ST50 that I removed and sent down for a replacement […]

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