Through Hull

[gfm]

<P>Has anyone had a problem with Apelco 360?&nbsp; Worked OK until this year when it began to give some rediculous readings.&nbsp; Basically, it says the water is 2 ft everywhere - shut it off and on and it works fine for a few minutes (sometimes longer) - ultimately it reads 2 ft.</P><P>Ratheyon told me that it was due to bottom paint w/ copper and that that was causing interference they said remove that paint and should work fine.</P><P>My boatyard says that is BS and that they have been painting them longer than I have been boating - these guys in all other respects have been very good and really know their **** - so I doubt they are wrong.</P><P>Apelco's answer: of course they say it's not the paint - they painted the bottom.</P><P>Any thoughts before I put the boat in the water - then it is too late (obviously I will remove the paint).</P>

[reel25]

I work for the company that makes the transducers for Raytheon. My first question is, did the Apelco work ok
before the copper based paint was applied? If it did, it
seems reasonable that it is the paint. If it did not,
obviously the paint has nothing to do with the problem.
Metal does not normally cause
a problem unless it is placed in a way to interfere with
the acoustic energy being transmitted into the water, then it can cause false echos and confuse the sounder. My guess
is that if the paint is the problem, it is causing multiple
echos off of the hull from the return signal off the bottom.
Try holding the transducer in the water outside the hull and
see what happens ( after you block the flange hole!). Also if the face of the transducer got painted, that will most certainly cause a problem as the acoustic energy won't be able to couple with the water. Hope this helps.