depth sounders

[Viscount]

I have a Sealine 285 fitted with the original Stowe Navsounder (through hull sender) and a new Furuno Fish Finder with transom mounted sender. With the fish finder on 200khz, the Navsounder goes nuts so I don't have both on at the same time. However, irrespective of which I use, the depth reading is lost once the boat gets to about 12 - 16 kts. I have received conflicting advice about this from "you'll never get depth readings once planing" to "mine works at all speeds".

Anyone able to comment from experience and suggest what, if anything, I can do to improve the situation?

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[DepSol]

My Lowrance used to work at speed up to 20 knots I think.

<hr width=100% size=1>Dom

<A target="_blank" HREF=http://www.soltron.co.uk>the website</A>

 

[discovery2]

I have a Furuno plotter/depth sounder.

Like you, at speeds of 12 knots plus, the depth sounder readings are either very erratic or no display at all. I can only presume it is due to the water turbulance past the transducer.

David.

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[itsonlymoney]

My depth sounder is very erratic at times when on the plane, and always useless if I have any trim tabs down. I think its just one of those things.
Regards-Ian

<hr width=100% size=1>Play the best game you can with the cards you've been dealt ! ! !

 

[TwoStroke]

I have an old eagle fish finder / depth sounder - works upto max speed of boat - 34knts. Is mounted on the transom and at a slight angle to reduce effect of the water.

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[gjgm]

A depth sounder can work at any speed.. its not the speed that is causing the problem,per se, its the increased disturbance of the water under the hull. I fiddled about to find the right point with my fishfinder to mount the transducer, and get readings at 40 knts with a stepped hull. Theres lot of posts here and PBO on how to test where to put the transducer. Guess you can see if you can remove the fishfinder transducer, buy another, but probably cheaper to buy a whole new fishfinder and start again ! What you have to locate is where the flow of water is still clean when the boat is on the plane, or all those bubbles get registered as readings... make sure there is nothing forward of that point that disturbs the water,is far enough aft to stay IN the water, and is far enough aft to be DEEP enough in the water

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[Oldhand]

Depth sounders stop working when the water in the vicinity of the transducer becomes aerated, finding a position on the hull where aeration doesn't occur is likely to be very difficult.

As depth sounder transducers typically only have a 30 degree cone in which they receive seabed reflections, at speeds in excess of 12 knots you would be very much looking at history in shallow water, rather than what is coming up so does it really matter?

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[Mike21]

Never seen that problem on any planing boat I've been on.
Did have a problem on S34 where the depth reading went when coming off plane, when tridata head fitted problem went. This is a Raymarine unit.
According to Raymarine agent may have been a software glitch and needed updating. Don't know if same with your depth sounder.

Appears Stowe Marine part of Simrad group so maybe worth asking their advice on problem

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[whisper]

I've had the problem on the last 3 boats I've had - should have learned how to avoid it by now/forums/images/icons/blush.gif
With Eagle Fisheasy 2 on current boat the reading also goes haywire if I've gone into reverse. Have to turn unit off, wait a minute or so and turn it back on to clear it. Even that doesn't always work first time.

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