Transom Mounted Transducer

[Jamie Dundee]

Thanks for the extra pics. Looks good.

By the way, does your propeller turn clockwise or anti clockwise (when looking ahead)?
Just wondered for prop wash being worse one side than the other when going along.

Mine looks to bite clockwise and the stern moves slightly to starboard when you put it in FWD.

Mine is right handed, clockwise in fw. In theory the quieter side should be to stbd but too many through hull fittings on that side which create turbulence.

 

[Pleinmont]

Mine is right handed, clockwise in fw. In theory the quieter side should be to stbd but too many through hull fittings on that side which create turbulence.

Thanks for confirming. Just goes to show that even the supposedly most turbulent side isn't that turbulent!

 

[Jamie Dundee]

Thanks for confirming. Just goes to show that even the supposedly most turbulent side isn't that turbulent!

Sikaflex a piece of ply to your transom and screw the td to that as a temporary mount to try it out. If it doesn’t work there’s no permanent damage.

 

[Pleinmont]

Good idea cheers!

 

[tillergirl]

Please forgive me intruding. Sikaflex is an adhesive - well 291 is. And once cured can only be removed mechanically (.e. ground out). I think it will marr the transom.

Could I ask, given that the images are all showing downscan. Is the transom 'ducer giving sidescan images please?

 

[Pleinmont]

Sikaflex a piece of ply to your transom and screw the td to that as a temporary mount to try it out. If it doesn’t work there’s no permanent damage.

Forgot to say earlier, would you scrape back the antifoul to the gelcoat (under the mounting pad) before applying the Sika?
I've just antifouled the hull

And would it be the 291i type Sika (assume that's the one)?

 

[Jamie Dundee]

Forgot to say earlier, would you scrape back the antifoul to the gelcoat (under the mounting pad) before applying the Sika?
I've just antifouled the hull

And would it be the 291i type Sika (assume that's the one)?

I would scrape back, but you only need to do a small amount for a temp transducer mount. Yes, 291i, I find it cuts off gelcoat ok with a sharp paint scraper, although you could leave it mounted that way if successful.

Could I ask, given that the images are all showing downscan. Is the transom 'ducer giving sidescan images please?

The last pic shows a high chirp water column with downscan bottom. The sidescan works fine at slow speeds in fairly shallow water, was the same on previous OB powered boat.

 

[Pleinmont]

I would scrape back, but you only need to do a small amount for a temp transducer mount. Yes, 291i, I find it cuts off gelcoat ok with a sharp paint scraper, although you could leave it mounted that way if successful.

Thanks - if I get time I'm going to fix the TD bracket to a stuck on mounting whilst the boat is out for antifouling this week.

In your pic it looks like the TD is underneath the exhaust - may be a silly question but does it drip hot water on it when you're going along?
The water level tends to drop away on the rear edges of the transom at speed but never looked directly under the bathing platform when cruising... It might not drop away in the middle so much.

 

[Jamie Dundee]

Thanks - if I get time I'm going to fix the TD bracket to a stuck on mounting whilst the boat is out for antifouling this week.

In your pic it looks like the TD is underneath the exhaust - may be a silly question but does it drip hot water on it when you're going along?
The water level tends to drop away on the rear edges of the transom at speed but never looked directly under the bathing platform when cruising... It might not drop away in the middle so much.

No, but running the engine on the hard allows me to monitor exhaust temp via the td/sonar ?

 

[Pleinmont]

No, but running the engine on the hard allows me to monitor exhaust temp via the td/sonar ?

Ha, i like it

 

[tillergirl]

Thanks.

 

[Breakin’ Bass]

Hi have just had twin transducers fitted to my merry fisher 805
Went down yesterday to have a look at there placement I will attach a couple of pics
She gets relaunched today so fingers crossed there are no issues

Hi, I've just been looking into fitting twin transducers to my MF 805. The issue I've come across is where they should go given that the fuel tank prohibits one going on the port side (stern) and I already have a transducer, engine water inlet and deck wash inlet on the Stbd side. Whereabouts have you fitted yours? Also how did you find your new set up? What MFD/Transducers did you use? Any advice most welcome. Thanks Pete

 

[Jabez]

Hi, I've just been looking into fitting twin transducers to my MF 805. The issue I've come across is where they should go given that the fuel tank prohibits one going on the port side (stern) and I already have a transducer, engine water inlet and deck wash inlet on the Stbd side. Whereabouts have you fitted yours? Also how did you find your new set up? What MFD/Transducers did you use? Any advice most welcome. Thanks Pete

 

[Jabez]

Hi
They are mounted towards the front so the cavitation from the prop does not interfer with the signal they are Raymarine HV-300THP HyperVision with a Raymarine elements HV MFD haven't used it as much as I would have liked to due to lockdown but I am very impressed with it the few times it has been used don't know where you are based but marine tech in gosport fitted the transducers for me

 

[Breakin’ Bass]

Hi
They are mounted towards the front so the cavitation from the prop does not interfer with the signal they are Raymarine HV-300THP HyperVision with a Raymarine elements HV MFD haven't used it as much as I would have liked to due to lockdown but I am very impressed with it the few times it has been used don't know where you are based but marine tech in gosport fitted the transducers for me

Many thanks for the swift response. I’m in Cobbs Quay, so will definitely give Marine Tech a call. Thanks again.

 

[Pleinmont]

If the through hull is not practical don't rule out transom mount transducers for inboards. It goes against most popular views but if you mount it far enough to the side and not in line with any intakes you can do get a decent signal and not much different to a boat with outboard/IO.

I have an Antares 760 with inboard and I sikaflex'd a temporary mounting to the stern with a Simrad 3 in 1 transducer screwed in. I did this because I wasn't sure if would work and might want to move it but it's been perfectly useable so in hindsight I could have mounted permanently in that spot from the start. I'll do it later this year next time it's out.
The board is a square of GRP with a block of HDPE neatly bolted to it for the exterior (apparently you can't bond HDPE very well). The Sika seems pretty solid for now. Pics below.

Some screen pics here of the sounder working when underway - the traditional 200/80khz and all Chirp modes track well up to my top speed of 20knts with no major issues from the prop wash.
Sidescan and Downscan work great up to 5knts which is as per the manual.
You can see the sidescan picking up all the steel pillars of the quay as i drive past about 50ft away, the details are amazing.

 

[Jabez]

Many thanks for the swift response. I’m in Cobbs Quay, so will definitely give Marine Tech a call. Thanks again.

I was just going through some paperwork and found the invoice for the installation from marine tech it cost £279.00 for the 2 tranducers to be fitted properly

 

[QBhoy]

Get a big blob of Vaseline and try it inside the hull in a few locations, sat in the Vaseline with no air bubbles in it. You’ll find somewhere for it to work. Once found. Mount in CT1 or similar

 

[Jamie Dundee]

Get a big blob of Vaseline and try it inside the hull in a few locations, sat in the Vaseline with no air bubbles in it. You’ll find somewhere for it to work. Once found. Mount in CT1 or similar

Shoot through hull is ok at lower frequencies, 50/200kHz, but won’t work with 455/800kHz. If mounting shoot through I’d rather mount in a liquid bath than add another layer of potentially air bubbled solid, and any form of silicone will degrade the signal.

 

[QBhoy]

Shoot through hull is ok at lower frequencies, 50/200kHz, but won’t work with 455/800kHz. If mounting shoot through I’d rather mount in a liquid bath than add another layer of potentially air bubbled solid, and any form of silicone will degrade the signal.

Don’t know too much about their hz to be honest. But I know that any I’ve had always works inside the hull after finding a good location with Vaseline first. Most recent were a Garmin 450s and very recently a dual hz transducer for a raymarine down vision unit.