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Depth Finder Stops Working

Discussion in 'Boat Electronics' started by frank1492, Jul 9, 2006.

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  1. frank1492

    frank1492 Guest

    It seems stuck at 2 or 2.1 feet. I checked the paddle wheel
    before launch, removed the barnacles, and it spun freely.
    Any ideas as to where the trouble might lie?
    Thanks in advance!
  2. GBM

    GBM Guest

    Paddle wheels on a depth finder?

    Maybe the paddles wheel stops turning when you are in very shallow water ;)
  3. Don't forget to check your VHF antenna.

    Glen "Wiley" Wilson <usenet1 SPAMNIX at world wide wiley dot com>
    To reply, lose the capitals and do the obvious.

    Take a look at cpRepeater, my NMEA data integrator, repeater, and
    logger at
  4. Larry

    Larry Guest

    Well, Frank, I see they've all had their little fun, so let's see if we can
    find the depth sounder transducer. You've already cleaned the speed wheel
    on the log....

    The depth transducer is different on different kinds of boats. Tell us
    what kind of boat you have, what brand/model of depth sounder it is so we
    can identify (correctly this time) the transducer and trace out the
    cables...which is probably the problem....

    If you have barnacles on your hull, there may be an incrustation on the
    surface of the depth transducer under the boat and that may be the problem.
    Had the hull scrubbed lately?
  5. This HAS to be one of the best postings yet! Even my wife laughed, and she
    doesn't even sail!
  6. Alec

    Alec Guest

    Could be that the transducer is mounted inside the hull and has been
    dislodged and is now measuring it's distance from something inside the

    Find the transducer.

  7. frank1492

    frank1492 Guest

    Hello All-
    For starters, will the wise guys (and their wives) who thought I
    was so stupid please google "paddle wheel transducer" and see what
    comes up? Thanks.
    To the others, the boat is a 1988 Grady White Seafarer with a
    thru-hull transducer.The paddle wheel is located left of center about
    2-3 feet forward of the stern. I do not recall the manufacturer of the
    depth finder. I will check tomorrow. (Boat currently at mooring.)
    There are no obvious irregularities on the hull and the boat was
    just launched so no opportunity to accumulate marine growth.
    The problem occurred rather suddenly.
    If the transducer is mounted inside the boat, I would assume
    it would be found just above the port above the paddle wheel,
    correct? And could that port be clogged with barnacles even though
    the paddle wheel itself appeared clean?
    I will try to find that transducer and hope it is not mounted
    under the gas tank!
    Thanks to those who have tried to help.
  8. frank1492

    frank1492 Guest

    Now I get it. You all had a right to laugh. Actually it made much more
    sense that the paddle wheel should measure speed, except I have
    no speedometer on this boat!! (Never did have.)
    My guess is that the depth finder transducer is mounted to the
    floor just below the engine. Checking tomorrow...
  9. GBM

    GBM Guest

    Frank - It could be that you have a tri-ducer - these include both paddle
    wheel for speed, depth transducer and temperature. It is possible that you
    have one of these with just the depth hooked up. Just follow the cable and
    you will find out.

    If it is reading a low fixed number, you may have a bad connection or the
    transducer or sounder may be bad. Maybe you could borrow a transducer and
    hang it over the side while plugged into your unit? This should be the best

    Good Luck
  10. Frank,

    It ain't what you say, it's the way that your say it! You had us all fooled
    anyway, and I must confess I have learned something after 50 years sailing,
    that there really IS a paddle wheel/transducer combined! We all have to live
    an' learn!

  11. Jack Erbes

    Jack Erbes Guest

    I get a lot of hits on transducers that measure flow or movement,
    nothing about depth. And it was a statement made in ignorance that was
    funny when read. It is that simple.
    Not necessarily. It could be a in hull, thru hull, or transom mounted
    model. Look at them here:

    I'd expect to find anything from a nearly flat surface (about the same
    amount of protrusion as a through hull inlet or discharge fitting) but
    with no hole in it. Or maybe a smoothly faired lump of bronze with an
    inch or two of protrusion.
    A transducer is not a port, it has no opening or hole. It is like a
    small combination magnetic speaker and and microphone. It generates
    sound waves (inaudible to the human ear) that travel through the water.
    Then it shuts up, listens for a return, and sends that back to the
    display module where the return is processed.

    It will generally look like a flat surface and will be aimed more or
    less straight down. Forget the paddle wheel. It has nothing to do with
    depth finding. Forget anything that might have a hole in it. Look for
    something that looks something like the ones in the photos at the Airmar
    Unlikely location. But the short slightedness of boat builders can't be
    underestimated. Worst case, if you have a display, follow the coaxial
    cable that comes out of the back of the display and you'll find a
    transducer. Or you may find a pair of wires that go to a a processor
    (the brains of the operation) that may be mounted below decks in the
    same general area as the transducer.
    You're welcome.

  12. frank1492

    frank1492 Guest

    Thanks to all for your follow-up on my problem,
    particularly to Jack
    When I get out to the boat (maybe not until tomorrow)
    I will get the manu. of the unit and look at the display with the
    line to the transducer disconnected to see if I get the same
    reading. Probably nothing conclusive from that but I'd like
    to see what happens.
    I now think I do remember seeing that transducer when
    painting the bottom. It was, as Jack said, like a plugged
    thru-hull fitting, and I think it was the same distance forward as the
    paddle wheel, though on the opposite side. If that's the case
    the top parts of the two transducers are easily visible under
    the engine, and I have seen them many times.
    I will keep you posted, and thanks all again.
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