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Discussion Starter #1
Anyone have any first hand experience mounting a transom transducer :confused:

Always hate to have holes in the boat, could it be put on with 5200 :confused:

My old instruments are shot and I want to go from this to this..

hatch.jpg

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Hey,

In 2007 I was updating the electronics on my new-to-me O'day 35. I bought a Lowrance plotter with sonar. It came with a transom mount 55/200Hz transducer. I wasn't exactly sure where I wanted to mount it. My first attempt was in the head, right in front of the keel. There is a removable access panel that gave me easy access to the hull. Since I wasn't sure this would be a good place, I used a wax ring for mounting a toilet bowl. I pressed the wax against the hull and then stuck the transducer into the wax. I checked the display and it was fine.

Fast forward to now and the transducer is still in the wax and still working fine.

Barry
 

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Discussion Starter #3
Thanks, I may go that route but I wanted the transducer to also measure boat speed and water temp, although water temp is more of a luxury. The transducer will need to be in the water....ie...wet :laugher

The two useless gauges I currently have are for speed and depth. I've been using a phone app for speed and I assume it's accurate but I'm always scared of getting the phone wet or worse.. :eek:

I figured buying one of the fishfinders would get me GPS, speed and depth for under $500.

I was going to remove the old instruments and make a nice teak plate to cover the old holes and flush mount the fish finder into the teak.
 

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you do know that some transom mount transducers and most fishfinders can shoot thru hull right? like barry says

you can test by putting you transducer inside hull over a bag filled with water and move around till you find a decent steady reading...

if your hull is not cored thats all she wrote...

I just bought a garmin 150 fishfinder and will be doing this shortly

ps. there will be too much turbulent water and or air, stern wave, heel degree, etc... to mount a transom mount transducer on sailboats...wont work that way unless motoring flat.

cheers
 

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Discussion Starter #5 (Edited)
Thanks.....If I'm not going to be able to get boat speed, I may just send the old Signet instrument to them for repair/estimate.

Buying a fishfinder was really for GPS/mapping and depth and was more of a cool luxury. I'm on a deep inland lake, I'm not getting lost and I really don't anchor out :laugher:laugher

I was on the Signet website last night and they want over $400 for the same unit which seems silly in this day and age....all it does in measure knots.....:confused:

They say they can fix/refurbish older units and provide price quotes in 2-3 weeks....I could not find anything on my depth sounder aside that they were bought by Garmin a few years back.

So, the consensus is that I can't get speed on a transom mounted instrument on my sailboat......???

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I have the exact same signet...

I only have the transducer which is good and still mounted...but there is no way in hell Im paying close to 400 for a display

so I went fish finder route

there was another thread where some nice guys posted on how to use an old transducer with a new display...can be done easily depending on what display you can get a hold of...

ps for speed you will be better than sound on the transom but on sailboat you always will have turbulence or at the least not the best waterflow for such things...
 

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Discussion Starter #8 (Edited)
You can get your speed (over ground anyway) from the GPS.
Oh, really :confused: So, if it has GPS it'll generate boat speed...??

That's really all I want, I'd like to see what sail trimming does for boat speed. I figure it's the only way to learn positive and negative effect. I learned yesterday that the boat went faster when I had the main reefed....in moderate gusty winds...

All I really want is an inexpensive way to have a map of the lake, measure depth and measure speed without putting a hole/holes in the boat. The Signet unit runs off of a paddle wheel installed under the vbirth, right next to it is the transducer for the old broken Interphase unit.
 

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Im confused by what you are wanting

if you want boat speed a paddle on the stern is not going to work well on most sailboats cause of the things mentioned before...turbulence, air popping in and out of water etc...

if you dont need or want speed through water there is no reason at all for any sort of transducer as any handheld gps does this for you

over GROUND...

you can tune your boat speed wise with either method however gps will be more accurate in certain situations...

at first I thought you were talking about depth sounders...
 

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Hey,

There a many different transducers out there.

The cheap transom mount units usually only measure depth. If you want to measure Speed Through Water (STW) then you need another transducer with a paddlewheel, and that does have to be mounted in the water. I think there might be some speed transducers that don't have a paddlewheel, but I'm not sure how well they work. All GPS units will provide Speed Over Ground (SOG) and that's usually good enough. If you boat in a lake, and don't have to deal with currents, then STW and SOG SHOULD be the same (or real close).

So a cheap GPS / Fishfinder should do everything you want.

If you want to spend more money and get the best system, there are triducers out there that measure STW, Depth, and Water Temp. That will have to be through hull mounted and they cost about $150.

Barry

Thanks, I may go that route but I wanted the transducer to also measure boat speed and water temp, although water temp is more of a luxury. The transducer will need to be in the water....ie...wet :laugher

The two useless gauges I currently have are for speed and depth. I've been using a phone app for speed and I assume it's accurate but I'm always scared of getting the phone wet or worse.. :eek:

I figured buying one of the fishfinders would get me GPS, speed and depth for under $500.

I was going to remove the old instruments and make a nice teak plate to cover the old holes and flush mount the fish finder into the teak.
 

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Discussion Starter #11
While I appreciate everyone's feedback, sometimes this site is frustrating. It's like nobody looks at a link or picture. You can buy fish finders that have a transom mounted "gadget" that does speed, depth and water temp all in one unit.

My basic questions was if these worked on sailboats and how would one install the sensor without drilling holes......ie....5200 adhesive... It appears not.

I'm gong to pull out the broken old instruments and find a GPS fish finder with depth and be done with it, I don't need exact speed, I don't need water temp, its accuracy can't be any worse than my phone.

I'll buy something I can mount to the inside of the hull.

Thanks
 

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I thought I was clear they dont work on sailboats...if you want all sensors...

ps there are MANY threads on how to install these in hull

baby oil
wax
silicone
epoxied

etc

use the water bag method and call it a day

likewise it seems you didnt have your question correctly thought out since you showed 2 linkes if the displays...
 

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While I appreciate everyone's feedback, sometimes this site is frustrating. It's like nobody looks at a link or picture. You can buy fish finders that have a transom mounted "gadget" that does speed, depth and water temp all in one unit.

My basic questions was if these worked on sailboats and how would one install the sensor without drilling holes......ie....5200 adhesive... It appears not.

I'm gong to pull out the broken old instruments and find a GPS fish finder with depth and be done with it, I don't need exact speed, I don't need water temp, its accuracy can't be any worse than my phone.

I'll buy something I can mount to the inside of the hull.

Thanks

To answer your question....using 5200 would be silly. Stick the darn thing on a flat spot in silicone (not through the keel of course)...it works fine. Use your GPS function for SOG and call it a day.
 

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While I appreciate everyone's feedback, sometimes this site is frustrating. It's like nobody looks at a link or picture...
FWIW, this site's picture attachment feature is very flaky. It does not display properly on some computer browsers and cell phones. On my phone, it displays, but is SO TINY, and sometimes the black space is all that shows up because the picture itself is off the screen to the side with no way to pan it onto the screen. (As soon as you touch the screen, it disappers.) Some other embedded pictures don't even show up, and you can't tell that they are missing.

So if you think that people don't look at your pics, you might be right. But it might not be their fault.

Back to your subject, IMO you only need SOW if there are currents. In a lake it is likely that SOW=SOG, so your GPS speed should be plenty good.
 

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Faria http://faria-instruments.com/index-marine.ph makes a depth meter with both ambient air and water temp displays. They are available with thru mount, inside hull mount and transom mount transducers. Water temp may be innacurate with an inside hull mount, but close enough for approximate readings. If I were me, I'd mount an inside hull transducer in silicone in a solid glass hull only. I am considering buying one this year if I get favorable reviews on a new thread I started regarding Faria instruments.

Speed can be measured with an inexpensive hand held GPS. I got one free for test driving a new Cadillac several years ago.
-CH
 

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Let us know how it goes azguy. I've got a shoot-thru-hull transducer and so far haven't been able to find a place to get a reading using the bag of water trick, squishing it down in wax, or placing it into my bilge after intentionally filling it with water. My next plan is to find an inconspicuous place to sand off the interior hull texture to see if that does anything. People on the Catalina Direct forums have gotten them to work though, so I know it's possible.
 

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Let us know how it goes azguy. I've got a shoot-thru-hull transducer and so far haven't been able to find a place to get a reading using the bag of water trick, squishing it down in wax, or placing it into my bilge after intentionally filling it with water. My next plan is to find an inconspicuous place to sand off the interior hull texture to see if that does anything. People on the Catalina Direct forums have gotten them to work though, so I know it's possible.
chip-
If you put the transducer in the bildge, are you above the keel? Try a spot in front of the keel.
-CH
 

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Discussion Starter #18
The best and most common spot I see is under the vbirth, the old one currently installed in my boat is located there and from doing all this research it appears to be the "no brainer" place to install it..
 

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transducers are able to read thru fg hullls...
transom mounts are great....if you wish to see how deep it was where you rAn aground...... " whatsa behind me is nota importante...." (gumball rally)
i had fishfinder trandsuducer that was installed under cockpit of my full keel ketch...lol.... might be good for med mooring, but in reality it was and still is crap.
do yourself a favor. get the correct transducer and figure out how to mount inside hull reading thru it. do not use sillycome as it makes bubbles you cannot get accurate depth. oil in a nicely installed tube works well...... other ways to mount work well also.... have at it
 

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I mounted my transducer inside the boat just starboard of the keel (about 2 feet). I used plumbers putty to hold it in place. I get EXCELLENT sonar results even when heeled. And the water temp is accurate too (it just takes a little while to register any changes); since it is essentially bonded to the hull, the temp seems to transmit very well through the solid fiberglass bottom (no coring there).

I feel very strongly in minimizing the number of holes in the hull. This avoids one entirely - with excellent results. With my particular boat's shape, a transom mount would NOT work at all: turbulent water and sometimes out of the water.

I get speed (SOG) through the GPS module. Yep, I know it's not precisely correct as Speed through the water . . . but it's dang close for my intents. But more importantly it's all relative. So, if I'm trying to tune the rig, I can instantly see if (for example) moving the jib car aft speeds things up . . . or slows it down.

I use a Lowrance hds5 for under $500. I LOVE IT. small and compact, built internal GPS antenna, loads my Navionics SD map cards, awesome graphics. its great.

Hope it helps.

~markb
 
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