Turn off your echosounder?

[boatless]

If this is true, should we only use echosounders when we're actually watching the depth?

<A target="_blank" HREF=http://news.bbc.co.uk/1/hi/sci/tech/3680086.stm>http://news.bbc.co.uk/1/hi/sci/tech/3680086.stm</A>

Personally, I've always left it switched on from departure to mooring, but think I may modify that.

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[webcraft]

I don't think yacht echo sounders cause any distress - the dolphins that come to play round my boat seem happy enough.

But - I may be wrong . . . does anyone have any proper scientific input on this?

- Nick



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[oldharry]

Depends what boat you have. If you happen to be running an ex MOD converted Frigate or Mine sweeper, or perhaps you have converted an old cruise ship? Otherwise its 'large modern ships' and Low frequency miltary sonar that appears to be causing the problem. But not yer bog-standard Nasa sounder or whatever which at 200khz is I am told above the range to cause problems to Dolphins etc.

Unless a marine life expert on the forum knows better....? If so we need to know.

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[Sea Devil]

The problem I have had is that I cannot turn off my echo sounder -

it is a Ratheon ST60 linked to the log, wind, autopilot etc by their interface - I tried putting a switch into the echo sounder part of the circuit but that just sent the system into breakdown mode...

The thing drives me crazy on passage telling lies about the depth and blinking away night and day for no reason - Sometimes it sends me into panic mode by suggesting there are only a few feet under the keel only because the depth is off the clock.
Any one know a simple way of cutting it out of the system once you are off shore and don't need it?

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[Shanty]

NASA supply an excellent low tech solution withtheir echo sounders - a plastic cover. Might even fit your ST60.

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[Sea Devil]

So do Ratheon - good thought - Will try it - but it still seems a waste of amps to have it working for no reason.........

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[ShipsWoofy]

I have heard this before but never seen it reported. The last pod of dolphins that swam with us sent my fishfinder into turmoil to the point I switched it off as I was getting alarm after alarm as dolphins skimmed the transducer.

I often turn it off, if only to conserve power. I will try to modify my behaviour and ensure it is definitely off in the future. Reading the article it is not hard to believe with all the man made noises down there that all the creatures must have tinnitus by now.

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[jonjo]

> waste of amps to have it working for no reason...

Think you will be less likely to have a close encounter with a submarine with it turned on.

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[Boathook]

Re: Turn off your echosounder? re jonjo

I have heard/read the same thing about subs elsewhere many years ago. My system being an early stowe dataline the echo sounder is on when the instruments are on. The later ones allowed you to turn it off to save power but for my voyages (across channel etc.) this is marginal.

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[Rob_Webb]

Deterrent

I know several blue-water cruisers who are happy to leave them on as a deterrent to all sort of 'nasties' notably subs, whales, orcas etc. I've heard it said that many of the vessels unlucky enough to be attacked didn't have sounders on at the time. But if that doesn't work, pouring some diesel into the water gets rid of them soon enough too. Probably upsets the Greens but could save your hull if they are starting to bump you around.

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[Guest]

Read the article you link to ......

I have a point though ..... the sources it quotes for noise are extremely strong sources and an echo-sounder as we use is not even a 'drop in the ocean' compared to them.

eg : Seismic pulses are in the magnitude of a dynamite charge - literally. They average shots every 7 - 11 secs depending on speed of the vessel ............ (To give credence to my statement here - I worked for 2 seismic companys : CGG and Western before leaving the sea)
Second the sonar pulse from military is also much sronger than your eco-sounder.

There is nowhere in the report about low power items such as ours .....

BUT I do think that man is guilty of blind actions and doesn't often equate the ecological damage done. So maybe there is a case to answer - but the report does not cite low power items.

Interesting debate.


<hr width=100% size=1>Cheers Nigel http://groups.yahoo.com/group/gps-navigator/ http://groups.yahoo.com/group/searider/

 

[Sea Devil]

I am not certain that my Ratheon echo sounder has any impact on dolphins or whales.
They regulaly swim around Bambola when on passage - almost daily sometimes.

I have had quite large whales come over to say hello - swim under the hull - beside me - all that with the blasted echo sounder pinging away because I cannot find a way to turn it off.

If they found the pinging offensive they would keep away I would have thought?

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[Birdseye]

Your depth sounder is very low output - thats why you can power it on a sailboat. And in any case, is not your survival of more interest to you than the comfort of a dolphin? It is to me.

So I will continue to use it if anywhere near land. If in mid ocean - well I would want to save the electricity by switching off.




<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.

 

[boatless]

Was thinking of a typical Solent day, say Hamble to Lymington, via Yarmouth. Would only actually need it for the Calshot corner, since I know the edges well from years of tide dodging while racing. I do most miles in Greece, and there it's only any use when parking.

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[ColinW]

They have a low average power because the pulses are very short but the power in the pulse is quite high. The pulse output on my fishfinder is 100W RMS. I wouldn't like to stand in front of a hifi speaker putting out 100W RMS pulses at a frequency that I could hear! Can dolphins hear 200kHz?



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