Transducer installation

[Dexter]

Has anyone installed a transducer in the keel of a 31 TE. I just purchased a 31 TE and want to install the Simrad structure scan but I would have to install 2 transducers because the keel is in the way. So I was wondering if one can be installed in the keel. If I install it in the keel I would only need one transducer which would save me about $500.

[RobS]

AOG member mhanna installed structure scan this offseason. I helped somewhat when he needed a second set of hands. I beleive we installed a single ducer on the starboard side of the centerline and he only notices the keel interfering with the sideways sonar to port in very shallow conditions. When I say keel I am referring to the centerline of the v hull, not the skeg as the ducer is mounted considerably forward of the skeg.

PM him or he should chime in here.. I must say, the sidescan imagery exceeded both of our expectations.

[Dexter]

I am in speaking with him. I called Simrad and they said I need two ducers (expensive) that's why I was thinking of mounting it on the Skeg. So the ducer is mounted toward the bow? Does mhanna have a 31TE?

[RobS]

He has a 28TE engine box model. Basically same setup as a single screw 31 just scaled down. Yes towards the bow, I would say about even with the back end of the pilothouse or midship cleat..

[mhanna]

Dexter, I installed the structure scan unit this spring and went with only 1 transducer for my install. Yes the Simrad guys suggested going with 2 if I had a deep V. I removed an old transducer and re-used its location, my plan was that if I had poor visibility to my port (it is installed on my starboard) I would fix it next year. The good news is it is working very well and I have no plans on adding a second one.
I might have lucked out as the placement is forward of the keel and close to the center-line.

ss.jpg

As Rob mentioned, I have some limits when in shallow water but not enough to make me change anything, see the below screenshot. The first was in 20ft of water near a bay reef, you can see the unit looks to the right 80+ft, to the left it gets a little dark at 70ft.


In the next shot I am in ~70ft and you can see the broken down barge in the lower left between 100 and 200ft to my port.

I am very happy with the unit and can see poles, blocks, etc in the water. If you mounting location is similar I would suggest trying something like I did, you can always add the second transducer later....

Let me know how it goes or if you have any other questions.

Matt

[mhanna]

Dexter I dont know if you are using the SS for fishing, diving or just to have a good bottom finder ? Here are more shots with the unit.
This one is in the Great South bay ~30ft water and it picked up a low lying barge to port.

shot 24.png

This next one is showing pods of bunker just outside FI inlet. I almost went right over them, that's why they are showing up in the right window (the "downscan" window) but you can see they really are to my port.

shot 19.png

This last one has sidescan, downscan and the regular fishfinder in the same window. The sidescan is looking hundreds of feet left and right so you miss fish. The regular color FF clearly shows 3-4 fish arches above a wreck, you can see the small white dots on the downscan (top left window) that shows the 4 fish as well, but if it where not for the fish arches in the other window I would have discarded those as noise.
I guess what I am saying is that while the structurescan unit works great for certain things it needs to be augmented with a regular FF for things like this.

Clip0021.jpg

I have only used this unit 3-4 times so far, as I mentioned before I am impressed with the unit but like anything you need to understand how it works to interpret the results. Here is a good video of how to understand it (it for Hummingbird but the concept is the same).
http://www.youtube.com/watch?v=3xe6pLPd ... re=related


Matt

[Dexter]

Thanks mhanna. You saved me a bunch of money. If I remember correctly, I think I have a transducer in about the same location as yours. I'm gonna try it. Which unit did you buy? The 12 or 8 inch. I seam to have room for the 12 (if I squeeze it in) but the 8 will fit more comfortably. If you have the 8 inch, do you find it to be too small?

Thanks for your help (the pics were great)
Anthony

[Dexter]

Forgot to ask, which fishfinder transducer did you get. I was reading the the 31TE has a 14 degree deadrise. Simrad recommended the tilt element B164-12 They stated it covers 8-16 degree deadrise.

Thanks again

[mhanna]

I will try to summarize the process I went through when choosing a MFD (and that was not my intent).
My original plan was to just replace a CRT Si-Tex unit with a newer and better FF. I wanted the structure scan feature and that led me to choose a Lowrance or Simrad display. The Simrad NSE (NSS was not out yet) was double the price and this was to be a FF so I went with the Lowrance HDS8. The HDS8 has GPS, regular FF features, etc.. After installing and using the unit I find that I am using its GPS chart plotter, FF, SS, etc.. I am very happy with the unit and how it works, the only issue is it is slow when changing screens. Because I am using it for alot more than I planned on I may now have made a different choice.

Getting back to your question about screen size, I have the 8" and find it is fine. What is interesting is that the SS module creates its "picture" with more resolution than the 8 (and maybe then 12 can display). Kind of like taking a picture with a good camera and then refitting it on your PC monitor. It works but you loose details. Details are important when looking for things underwater. The 8inch unit does 800x600 pix, the 12 inch does 1024x768. I'm not sure how much those extra pix will do but it will be better.
In the screenshots above you can see I run with a downscan window open, and sometimes even a GPS window. This takes away pixels from whatever you want to see. I plan on adding a second 8" unit later and this would allow me to free up screen room for more SS images.

I cannot fit a 12inch unit but as I mentioned (2) 8" ones can be done and they are supposed to be able to share display info and such. Keep that in mind when choosing.

And for the transducer I installed an Airmar P66 on the transom. I will be replacing that with a thruhull next year. Let me know what one works well

Matt

[Dexter]

I finally finished the install of the transducers. I located the structure scan aft of the keel. There is a nice flat spot there with unobstructed side view and no need to cut the fairing block. I could have installed it without the fairing block but I wanted it deep in the water to get bellow my shafts. I called Simrad to verify and he stated that it shouldn't be a problem there because it is an 8-10 knot transducer so at these slow speeds there should be no turbulence. I installed the Airmar B164 12 degree tilt transducer along side of the structure scan. My fiberglass guy installed it a little close to the center (I would have put it more laterally but it was installed before I noticed the exact placement and he said there was a stringer in the way) Hopefully i won't have turbulence in that location. I should be splashing today. We shall see.

[Dexter]

Thought I would post a pic of my new toy

[mhanna]

Anthony, looks like you might have found an ideal spot for the one ducer.
A friend of mine installed a transom mount ducer on a 31 twin screw Bertram and that ducer has to look through the propwash. It works well at 5-8knts, above that it looses some detail, but there is alot more turbulence in prop-wash than in a keel. I would expect it to be ok.

My first time out to see how it worked I was disappointed, what I did not know was that it was working fine there was just nothing to see down there but wavy sand. That being said, when you go out for the ride to test it try to go to a reef, rocky area, etc...

Let us know how it goes, good luck

Matt

[DougSea]

Thought I would post a pic of my new toy

She's looking fine!

[Dexter]

Thank you

[Dexter]

Just thought I would give an update about my ducer install. I was initially having problems with the fishfinder. I was losing bottom at speeds above 10 knots. I did some research and read about ping rates. So I raised my ping rate to maximum and now I get a nice clean image of the bottom at all speeds. So far so good.