Fishfinder

[Adamn]

Hi all I was out yesterday and found that over 6 kts it would not read the depth and kept flashing dots instead. It was fine under
6 kts.
Is this normal?

[Nos4r2]

Got a pic of the transducer installation?

[wavelength]

What make and where is the transducer?

[Adamn]

Hi the Fish finder is 5 years old and came with the boat. There were no booklets or manuals. The transducer is fitted to the right bottom corner of the transon. I have posted a couple of photos

[wavelength]

Have you got a drain well in the boat...a well at the stern where the grp is just single skin i.e. the outside water touches the other side of it ?

If so take the transducer off its mount, and just put it in the drainwell, you may want to wedge it with a bag of sand on top of it to keep it on place/right way up. Next time you go out chuck some water in the well so that the interface twixt transducer face and bottom of the boat is always under a bit of water.
Try it out.
Will work fine thru one layer of glass and hopefully will work at any speed. If it all works ok then when you get home dry it all out and simply fix the transducer in with some clear silicon avoiding air bubbles. Two pot epoxy is the official way of sticking it down but we jave always used silicon with no probs and being doing so for donkey's years. Can always get the transducer out again if ya want with silicon.
On the other hand it may just be kn******d but hopefully and probably not eh!

[Adamn]

Thank you for your input. Yes it has a drain well but under that is a hull plug for any water that gets in the hull. That would mean another skin? I have put up two photos of the transon you can see the hull drain below the deck drain.
I would agree that under way the transducer is not in full contact with the water causing lost data. I could try and change the angle so that it is facing down alittle more.
When I bought this Rib I looked at 2 before it and there transducers were in the same place.

[9D280]

Or tip the transducer to a slightly forward angle. (this may or may not work depending on it's position relative to the transom, but is an easy & quick test)

Might be worth loosening the bolt and dropping it's tail slightly (and tighten the nut properly hard) to make sure it is in good contact with the water. I need to find some new star washers for the "hinge" bolt on mine as it will slowly lift out with the pressure of water (takes a couple of hours of motoring), with the same result as yours -no depth reading.

At sub 6 knots it will be underwater so no problems with water contact.


Other thought - It's difficult to make out for sure, but is the mounting bracket below the bottom of the hull? If so that will be generating a ton of turbulence & air bubbles which will confuse the sounder module.

[Adamn]

Thanks for all the advice. The unit is not below hull level but the transducer is angles slightly up so I will loosen and angle down a little to see if that works.

[wavelength]

had seen that drain plug and wondered if it might be to drain the inner hull giving a second skin in the well ....which is unfortunate in not offering the in hull solution.

When I bought this Rib I looked at 2 before it and there transducers were in the same place

yep and thats the place the manufacturers prescribe for it. However far too many years of boating experience means I never put them there! Prone to damage if doing a lot of launching on the exposed sand and stone beaches here our bit of coast and they work far better in the well without having to cock about adjusting the angle of it etc etc. But its not an option here so angle twiddling it is
Look forward to hearing if you manage to sort it, keep us informed

[Adamn]

Thank you for your input. I will be twiddling around with it on Thursday but will have to wait till the 9th June to see if it works.