CLIPPER DEPTH SOUNDERS

[alisdair4]

Has anyone else had this experience? Last year I bought a Clipper Duet depth sounder and log combo. The log works perfectly. The depth sounder works less well - I changed its position this season, and went through a few months of the entire Ijselmeer being 0.7m deep. (after a time, you stop worrying!).

I sent the unit back to NASA for testing, and they were excellent - but told me the machine is working perfectly. Indeed, when I lower the transducer over the stern (ie, into the water directly) it gives an accurate reading.

The problem is clearly with regard to where on the inside of the hull I place the transducer. Nowhere appears to work - but my boat's hull is only about 3mm thick.

Any ideas?

<hr width=100% size=1>"so long as all you want is a penguin’s egg"

 

[bruce]

do you have a copper bottom paint? you may have to clean a small area of bottom in area of transducer to make work and use a non copper paint.

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[boatless]

What method are you using to acoustically connect transducer and hull?

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[ShipsWoofy]

<blockquote><font size=1>In reply to:</font><hr>

but my boat's hull is only about 3mm thick

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Are you sure? My gel coat is easily 3mm thick under the waterline.

Have you considered fitting it 'Thru hull', with epoxy and fibre glass to get a nice strong fitting this might be your best bet.

Just a thought

<hr width=100% size=1><A target="_blank" HREF=http://www.topcatsail.co.uk>Woof</A>

 

[Avocet]

I think they project a "cone" shaped beam downwards so take lines from where the transducer is at (I think) about 22.5 degrees outwards below the boat and see if any of them hit the keel(s) or skeg or anything like that.

Also, I think if you fit them inside the hull, you need to put them in a tube full of castor oil (with no air bubbles) so that the tapered gap between the transducer face and the inside of the hull is completely filled with oil.

I'd be amazed if your hull was only 3mm thick, mine (OK it's an old one) is about 20mm thick on average below the waterline. Even GRP cars are more than 3mm thick! That said, I've had my Clipper transducer successfully working through the hull but it looses its echo in deep water (say over 50m) Not that this is a probelm but if it was just the thickness of the GRP, it would be fine in shallow water.

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[graham]

i have mine sat in an oil bath inside the hull.(Nasa provide a kit) .Never had any problems with it ,the grp is about 10 mm thick in the bottom of my boat.

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[robind]

Have you installed it correctly inside the hull in the first place? is it to manufacturers spec? is it in an oil bath within a plastic tube attached to the hull?
I apologise if you have but its worth the question.
Regards
Rob

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[Jacket]

Mines set in epoxy, rather than an oil bath, and works fine. Only starts to loose a signal in depths of around 250m, though it does get very confused if there's a lot of sediment in the water.

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[milltech]

If you have a double skin it could cause your problem. You ought to be able to check different parts of the hull with blue tack and then glass the transducer in or use the oil bath method. There is always the through-hull method if all else fails, but you will need some kind of fairing to protect the transducer.

<hr width=100% size=1>John
http://www.on-line-marine.com

 

[alisdair4]

Thanks to all! I have now ordered the oil bath kit from NASA (£15) so we shall see what transpires..!


<hr width=100% size=1>"so long as all you want is a penguin’s egg"

 

[JamesS]

I haven't got a clipper, but when I ibstalled my ST50 some years ago I was advised to put the transducer into a polythene bag, fill with water and seal the neck.

You then move the thing around the hull untill you get the best reading.

This may sound crazy but I've used it several times and it does work!

Cheers

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