Conference unifix::sailing

I'd suggest a call to Datamarine (in Pocasset, MA, I think). They have a 
reputation for excellent customer service. It sounds like your
depthsounder is seriously broken and needs factory (or authorized repair 
facility) mending.

    I agree with Alan.  They are very responsive.  Some of your problem
    sounds similiar to one we had last summer.  It was a new unit.  The
    problem turned out to be the transducer - the reseller subsituted
    another one for the one which came with the unit - fortunately for us
    it was under warranty and was replaced with the correct one.  
    

    This is a crazy possibility but it happened to me.
    
    The yard launched my boat...I was not, due to an unavoidable conflict,
    in attendance.   They put bottom paint at all the unaccessable places
    the cradle block (gee thanx).  They also put some on the transducer.
    
    When this was removed, behaviour returned to normal.
    
    One other case history.  On a previous craft, I attempted to avoid
    drilling more holes, and mounted it inside.  Used various substances
    to attempt to achieve a good accoustic bond between the fiberglass
    and the transducer.  It worked, but never very well.  It especially
    liked not to work when motoring into (alway thought it might be
    as signal to noise problem) unfamiliar anchorages.  It loved to work
    when sailing in deep water.
    
    Good luck and let us know how you do.  Have the same equipment on
    current boat.
                 

    I have had the same flakiness with my Datamarine depthsounder, however,
    since it is ancient (uses gas-discharge tubes!) last year was the last
    year that Datamarine would look at it. Oh, OK, they'd look, but it
    would cost more to repair than to replace.

    One of the things that I had noticed was that by wiggling the RCA phone
    plug which terminates the transducer cable at the instrument end, I was
    able to get 'better' or more reliable readings. On the strength of
    that, I replaced the RCA phone jack in the instrument with one from
    Datamarine.

    At put-in this year, that fix was no longer enough. What seems to have
    cured things [so far] was to take the unit apart and re-seat the crimp
    pin connection from the RCA jack into the electronics. 

    If you have been getting readings either all over the map, or ones
    which appear to be maxed out, look for corrosion in the signal path
    between the transducer and board electronics.

    Good luck!
    Carl

    Regarding the comment on bottom painting transducers, I decided
    to give mine a thin coat of Micron CSC last year and experienced
    no change in performance.  The previous season, my sounder was rendered
    useless by marine growth and I thought it might be worth a try.
    One coat did the trick and since I used the same mooring and anchorages
    during the season I was able the verify performance.  The unit is
    a new (1988) Standard Horizon.  
    
    I've been thinking bold this year and may give the paddle wheel
    on my speed log a coat.
    
    The nice thing about the CSC is that it ablates almost completely
    by the end of the season, so you don't get any build-up.
    
    Bob
    (Splash date 5/29....T minus 12 and counting)

    On all the Moody & Westerly yachts that I have come across here
    ion the UK the transducer has always been mounted inside the hull.
    The euipment has either been Seafarer or Stowe or B&G. The transducer
    has always been sighted just forrad of the keel(s) and bonded in.
    Last season in Cherbourg my shore side skipper got a bit enthiastic
    with stowing the duty fre wine etc and dislodged the transducer,
    I resited it using Araladite and it worked fine. Cross checking
    against neighbours boats. Why have more holes than necessary in
    the hull?
    
    Pete
    
    

    The copper in bottom paint can interfere with the signal from your
    transducer.  This is why it's recommended that you paint the transducer
    with specific transducer paint.  Unfortunately, this was tin based and
    is impossible to find any longer.  If I had any old tin-based paint
    lying around waiting for proper disposal I might be tempted to paint
    my transducer with it.  Of course I wouldn't, you understand, because
    I sure believe in all of those laws.  No sir, you wouldn't catch me
    doing anything illegal like that.

I had a Datamarine unit with similar symptoms at first.  I recall using the
GAIN adjustment to settle the readings down.  This may have been due
to the location of the keel in relation to the transducer.


I also had to replace the male RCA connecter every other year (yes, solder it!).
One more thing, I replacd the female RCA connector on the unit itself once.

Corrosion does nasty things to marine electronics.


BTW, did you mention if the transducer was through-hull or not?  If it's in a 
"box" then make sure the fluid level is topped off.


DATAMARINE is not only helpful but also has good turn-around on repairs.

bc

    I recently purchased a B & G Focus depthsounder/speed combination
    unit. The installation instructions state that only "mineral-based"
    anti-fouling paint should be used.  The person at Interlux technical
    support (1-800-INTRLUX) said that their line of Bottomkote paints
    are suitable for transducers and Micron CSC is not suitable.

    Steve