3D Real Vision Transducer placement (Yacht)

[watsala]

Hello,

I am looking for some input about putting 3D Real Vision Transducer on a Hood 38 yacht and whether I can get away with 1 transducer instead of 2.

I am currently thinking forward of the keel on the center line on a fairing block would be best:

https://imgur.com/a/gq0TM

Q: Does the fore/aft line of the transducer need to be parallel to the waterline/oceanfloor?

https://imgur.com/a/KPt8g
https://imgur.com/a/l8HBv

I am also concerned that the threaded part of the transducer wont be long enough to go through the wedged fairing block and the hull.

Has anyone else done this on a yacht?

I was going to use the bronze transducers as I hear the plastic ones still have a few teething problems?

Cheers

W

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Watsala,

When properly installed, the transducer(s) will be oriented parallel to the waterline. As indicated within the Raymarine’s web site RealVision RV-2xx 3D Bronze Through-Hull Transducer Installation Instructions, it is recommended that for fin keel sailboats, that a transducer pair be mounted forward of the keel, ensuring that the keel will not obstruct the transducers wide beam width (see excerpt).



While installation of a single 0 degree transducer work as well, the custom fairing block which you have suggested would have to be well engineered to ensure that an non-aerated flow of water travels over the face of the transducer and may well not permit the transducer's shaft to penetrate the hull sufficiently to permit its securing nuts to be installed.

[watsala]

Hi Chuck,

Thanks for the welcome.

So it sounds like I am on the right track with my thinking. I will need to do some careful calculations if I try to get away with one to make sure that the shaft will be long enough.

If I go for two can they attach flush to the side of the hull (which I think is at least a 30 deg angle to the waterline, or do I need to get the ones with dead rise built in (which goes up to 26 deg? and compensate the difference with a fairing wedge?)

I dont have a exact cross section of my hull but I think it is close to this :

https://goo.gl/images/ydsxe4

Actually despite the picture I just posted - I dont think looking at this image of my hull it ever gets close to being parallel with the water line:

https://goo.gl/images/cKxFvJ

And probably quite a bit more than 26 deg.

Thanks

-Watsala

[Chuck - Raymarine - Moderator]

Watsala,

All vessels are not necessarily well suited for installation of such transducers. As suggested initially, installation of such transducers may additionally require some customization of the hull to accommodate the transducers. Please note that should you only be seeking to single channel high CHIRP (conical) sonar or traditional 50kHz/200kHz conical sonar, then it may be possible to alternatively interface the Axiom DV or Axiom Pro S MFD respectively to one of these transducers.

[watsala]

I measured the angle of the hull today in the bilges - its about 25 degrees so the twin real vision transducer should be suitable I think.

I was planning on mounting the same distance from the front of the yacht, but they might be slightly different distances from the center line. Does this matter?

They would also be on the hull slightly after of the front of the keel. Again is this ok or do they need to be forward of the keel?

Thanks again.

W

[watsala]

Here is the actual hull and where I want to place the transducers. Notice the port on will be slightly further away from the centerline and the are slightly aft of the keel.

Does this placement look ok?

Can you still do the test with the bag of water with the real vision transducers?

[Chuck - Raymarine - Moderator]

watsala,

Raymarine recommends that fishfinder transducers be installed forward of the keel on sailing vessels. Waterbag tests cannot reliably be performed with low power transducers such as DownVision, CPT-S, and RealVision 3D transducers.

[watsala]

The issue with mounting it further forward I think is that the dead rise angle gets too high.

What sort of issues might mounting it adjacent to the keel cause?

[Chuck - Raymarine - Moderator]

watsala,

Possible issues which could arise include the keel causing a turbulent flow of water affecting its ability to receive reflected sonar energy. The keel may also reflect sonar energy, which in turn may adversely affect sonar imagery.