FSH Transducer Placement

[Grover70]

Update to my FSH transducer placement.

After two misses, I was able to find the sweet spot for my FSH transducer. Through hull - no go
Transom - Lost signal after 20 knots, turbulence from the first step.
Third time...a charm.

Took my beat up Garmin 74dv transducer and a 1" thick board of marine grade polyethylene sheeting.
Traced out the transducer over the sheet and cut it out. Epoxied the marine sheeting to the top of the transducer with a cut out for the cable. Used marine grade contact adhesive/sealant to attach the top portion of the sheet to the aluminum beneath the jet nozzle, adjacent and ahead of the articulated keel. The 1" drop was to really get the transducer into the clean water.
Only one cable holder was needed to be drilled beneath the water line, and that was into the aluminum, so not through the hull. Additional anchors were into a stern-saver and then up above the water line. Protected the transducer cable from accidental hooks with a spiral cable protector. Also protected inside of the engine compartment since it's fire resistant.

The result: A very clean signal at max speed. Protected by the articulated keel and almost centered. No holes through the hull.

 

[SoftballBryan]

This is almost exactly what I have done myself. When I get the boat back from servicing, I'll take pictures and video and post here as well. The setup I used last year was temporary and couldn't handle the force of the water, so I've attached something more firmly such as you have done.

Easy side scanning capability

 

[Grover70]

This is almost exactly what I have done myself. When I get the boat back from servicing, I'll take pictures and video and post here as well. The setup I used last year was temporary and couldn't handle the force of the water, so I've attached something more firmly such as you have done.

Easy side scanning capability

Looks like I reinvented the wheel
I don't have side scanning though. I'd imagine the extra inch or so would really help in that situation with the keel.

 

[Wake Turbulence]

That looks good. I installed a transducer but did drill through the hull and I still lose signal at speed... I thought that was normal, is it not?

But I also only installed a basic Garmin.

 

[Grover70]

That looks good. I installed a transducer but did drill through the hull and I still lose signal at speed... I thought that was normal, is it not?

Hello!
I thought it was normal too and actually, it is...if there is turbulence being created from a strake or a step. Which is exactly what happened with mine. But, if the transducer is in clean water at any speed, then the signal should be just as clear as lower speeds. Once I dropped it away from the step, it was perfect. That's one of the reasons I added the 1" drop and placed it near the keel. Even jumping around in choppy water today at 32 knots the sonar and depth readings were quite accurate.

 

[highanddryinco]

Did you guys use any special epoxy on the Polyethylene? It doesn't seem to be the most adhesive friendly material ever made.

 

[Grover70]

Did you guys use any special epoxy on the Polyethylene? It doesn't seem to be the most adhesive friendly material ever made.

Hello. I used Ace hardware marine epoxy for the board to the transducer and Amazing Goop sealant and adhesive for the board too the aluminum. I kept constant pressure on the board to the aluminum for 24 hours with a tire jack and let it cure for 72 hours in dry moderate weather.

 

[veedubtek]

For a little more 'ducer talk - what if I don't have/don't care about sidescan? I've got DV capability, not sure if I care about that, likely not, but if I got it, why not right? I mainly got this thing for depth/charts/water temp. I'm thinking transom mount like Will (and out on the reef, and others) would be fine for me? Not sure I trust the "spacer" thing Will used, but I can't imagine he hasn't tested that thoroughly. Looks like just a piece of starboard? Don't really wanna angle it, although I'm sure the slight inaccuracy isn't gonna hurt me, just my OCD.

 

[Grover70]

For a little more 'ducer talk - what if I don't have/don't care about sidescan? I've got DV capability, not sure if I care about that, likely not, but if I got it, why not right? I mainly got this thing for depth/charts/water temp. I'm thinking transom mount like Will (and out on the reef, and others) would be fine for me? Not sure I trust the "spacer" thing Will used, but I can't imagine he hasn't tested that thoroughly. Looks like just a piece of starboard? Don't really wanna angle it, although I'm sure the slight inaccuracy isn't gonna hurt me, just my OCD.

If you don't care about sidescan, that answers your question. I didn't need it. I just use the basic features the Garmin 74 dv came with. What I don't have, I don't miss. I do like the DV capability and that's enough for me and my meager abilities. The transom mount was fine...under 20 knots. After that the first step just causes too much turbulence.

The way I look at the epoxy vs. screws: I have about 20 square inches of marine grade epoxy holding the 1" marine board spacer to the transducer and another 20 sq. inches of sealant/adhesive for the marine board to the aluminum keel. That's 40 sq. inches of proven, cured, adhesive holding that vs. a three small holes into fiberglass. I put my money on the cured adhesive having the best chances of withstanding incidental impacts, pressure, and wear, over 5/8" stainless steel screws into fiberglass.

My two cents.

 

[veedubtek]

How did you run your cable into the engine bay, @Grover70 (or anyone else for that matter). Got everything mounted, and I'm into the cleanout hatch. Not seeing a clear shot into the engine bay yet. The rest of the path is pretty clear from there. Looks like *maybe* the far port side of the battery compartment? Trying to drill as few holes as possible.

 

[veedubtek]

Nevermind, lol. Amazing what you can see with a flashlight. Mission accomplished.

 

[Grover70]

Nevermind, lol. Amazing what you can see with a flashlight. Mission accomplished.

Glad you got it done. I basically just followed the cable bundles through the engine, into the gas tank area, under the console and up to the mount. Didn't have to drill a thing. In case you want to do this too, I placed fire retardant cable wrap around my transducer cable in the engine compartment. I just don't know how much heat is generated in there and I wanted an insurance policy against the outside of the cable being slowly degraded from temperature exposure and the elements. It's got to be a pretty harsh environ.

 

[Anthony_bonanno83]

Update to my FSH transducer placement.

After two misses, I was able to find the sweet spot for my FSH transducer. Through hull - no go
Transom - Lost signal after 20 knots, turbulence from the first step.
Third time...a charm.

Took my beat up Garmin 74dv transducer and a 1" thick board of marine grade polyethylene sheeting.
Traced out the transducer over the sheet and cut it out. Epoxied the marine sheeting to the top of the transducer with a cut out for the cable. Used marine grade contact adhesive/sealant to attach the top portion of the sheet to the aluminum beneath the jet nozzle, adjacent and ahead of the articulated keel. The 1" drop was to really get the transducer into the clean water.
Only one cable holder was needed to be drilled beneath the water line, and that was into the aluminum, so not through the hull. Additional anchors were into a stern-saver and then up above the water line. Protected the transducer cable from accidental hooks with a spiral cable protector. Also protected inside of the engine compartment since it's fire resistant.

The result: A very clean signal at max speed. Protected by the articulated keel and almost centered. No holes through the hull.

I just bought a lowrance hook 7 for my FSH. Installed everything but the transducer because i was unsure where to place it. The tech at the boat store....marine max, told me where to run and mount the transducer. I think he was a moron now because he told me to run the cable through a pre existing hole in the back of my boat? I looked and no way that's happening. Thanks for the pics, I'm gonna follow what you did.

 

[Grover70]

I just bought a lowrance hook 7 for my FSH. Installed everything but the transducer because i was unsure where to place it. The tech at the boat store....marine max, told me where to run and mount the transducer. I think he was a moron now because he told me to run the cable through a pre existing hole in the back of my boat? I looked and no way that's happening. Thanks for the pics, I'm gonna follow what you did.

Glad that you found the post helpful. I went through two other methods before figuring this out: Transom mount and in-hull. Nothing worked with in-hull and the transom stopped working at 20 knots due to the disturbance from first step. I'm really happy with the results and I hope you are too.

Don't be shy with the adhesives! It took about 72 hours to cure but it holds.

 

[veedubtek]

I put my transom mount a little further over and down a bit with a transducer plate off Amazon:

https://smile.amazon.com/gp/product/B00ZX01YOS/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

Probably not as good as your placement, but does work well at all speeds.

 

[Grover70]

I put my transom mount a little further over and down a bit with a transducer plate off Amazon:

https://smile.amazon.com/gp/product/B00ZX01YOS/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

Probably not as good as your placement, but does work well at all speeds.

Looks pretty clean to me and should be out of the turbulence at that position. Nice work.

 

[Brian Filas]

So, I just picked up the new Carbon 9 with the TotalScan transducer. I have some ideas on mounting that I need to work out. Basically, i want to get it as far forward to avoid that second step in the hull (before the true transom). In the end, I think it will be another custom aluminum bracket. I also figured out a way to quick mount the unit and some organizers on the top of the console (and still get it in and out of the garage with minimal prep time). Just got all the parts this week so will be working on it this weekend and will post pictures soon. If that doesn't work, going with @Grover70 placement. Was worried about just using adhesive, but he has a good point about the punishment 3 mounting screws take anyway.

Glad to hear you didn't see any turbulence from the intake grate.

 

[Grover70]

So, I just picked up the new Carbon 9 with the TotalScan transducer. I have some ideas on mounting that I need to work out. Basically, i want to get it as far forward to avoid that second step in the hull (before the true transom). In the end, I think it will be another custom aluminum bracket. I also figured out a way to quick mount the unit and some organizers on the top of the console (and still get it in and out of the garage with minimal prep time). Just got all the parts this week so will be working on it this weekend and will post pictures soon. If that doesn't work, going with @Grover70 placement. Was worried about just using adhesive, but he has a good point about the punishment 3 mounting screws take anyway.

Glad to hear you didn't see any turbulence from the intake grate.

Looking forward to seeing your end results. The adhesive is as strong as ever even after a few trips at top speed.
I am not 100% pleased with my transducer cable as it makes contact with the dull edging of the aluminum under the nozzle (in pic). To head any potential wear/tear, I have reinforced the cable and added a cable stay. If I had to do it again, I would reposition the cable or add reinforcement before I mounted it. I inspect it after my trips and nothing untoward has happened to it.

 

[Ehren]

@Brian Filas , have you had a chance to complete your TotalScan transducer installation? If so, are you able to share any pictures as well as any feedback on transducer performance including side scan imaging?

 

[Grover70]

@Brian Filas , have you had a chance to complete your TotalScan transducer installation? If so, are you able to share any pictures as well as any feedback on transducer performance including side scan imaging?

This Garmin 74dv transducer does not have side-scan. Chirp and basic imaging. So far I'm very happy with the results though. Even at full throttle the depth and scans appear quite clear. No decay whatsoever of the adhesion. The design of the transducer helps it cut through the water, lessening stress on the adhesive.