How did you mount your depth finder transducer?

[AZ-Oldguy]

The depth sounder that came on my endurance 35 had a transducer mounted in a well up in the bow. It worked well enough, using flashing lights on a rotating disk to indicate depth below the Keel in fathoms or feet. But it was hard to read in bright light and was down in the Pilot House. A crew member had to be watching the Sounder and relaying information to the man at the wheel.
So when I got a new Raymarine Axiom 9 chartplotterlast year, I was looking forward to being able to see a graphic image of the bottom and the relevant depth readings in the cockpit on the chartplotter screen. Working with the local West Marine representative I have been unable to come up with mounting for a transducer that is available. The maximum deadrise that is allowed by the various Airmar thru Hull or in Hull transducers is about 24 degrees. The best I can do is about 45 degrees because of my large full Keel and Rudder occupying the center of the boat. As you can see from the one picture the little well that has been glued to the hull allows the transducer to be sitting in a well of oil. The readings seemed quite accurate when compared with a lead line.
If you have a full keel or cutaway Keel sailboat with a steep deadrise what do you do for transducers? I am happy to try and MacGyver a mount for one of the existing airmar transducers but I'm having a hard time getting any good information about what the Steep deadrise angle will have on the quality of the readings. It was suggested I might use a fairing with a through Hall transducer, but then when the West Marine rep looked up fairing blocks the maximum deadrise allowed on any of them was about 25 degrees. So I get a better signal with a thru Hull transducer but I'm still looking off to the side 20 degrees. If I enlarge the existing well and glue the housing that comes with the in Hull transducer to the top of the well, filled with oil, is this going to work for me? Unfortunately Airmar doesn't seem to want to talk to me. They will send me a catalog. But they want me to talk to a Salesman at a distributor. Local electronics installers don't want to even sell me the parts unless I am giving them the whole job of Designing and installing the system. I am pretty frustrated having enjoyed the use of this chartplotter for a year, but without being able to access its depth sounding or fish finding capabilities. Thanks in advance for your thoughts and experience.

Glenn

[Mike OReilly]

I have a full keel with a steep rise and a very thick hull. When I had to replaced a failed depth transducer a few years ago I ended up rebuilding the inside and external housing to allow for a vertical angle.

I bought the longest stemmed transducer I could source. Even with this, it was a challenge, but it worked:

AIRMAR

[roverhi]

Mine is mounted through the hull with plastic fairing block. If there is a lot of rise at the location, may require a longer threaded section on the transducer.

[AZ-Oldguy]

Originally Posted by Mike OReilly

I have a full keel with a steep rise and a very thick hull. When I had to replaced a failed depth transducer a few years ago I ended up rebuilding the inside and external housing to allow for a vertical angle.

I bought the longest stemmed transducer I could source. Even with this, it was a challenge, but it worked:

AIRMAR

Mike, is your transducer "through hull"? Or in a well?

[Mike OReilly]

Originally Posted by AZ-Oldguy

Mike, is your transducer "through hull"? Or in a well?

It is though hull — as in a big hole in the hull

[AZ-Oldguy]

Originally Posted by Mike OReilly

It is though hull — as in a big hole in the hull

Thanks, I figured that out after I looked at your airmar link. I noticed in the specifications for that particular thru-hull that it's designed for a deadrise of 24 degrees. That seems to be the max that they're advertising on any of these mounts. As best as I can figure my deadrise is about 45 degrees. It's a little tricky because the hull is curved in that location. So it sort of depends on what you're measuring.
Did you cut and glue your fairing block on to the hall yourself? And then drill a vertical hole through the whole thing? I am imagining a rather long extension bit on a 2 inch hole saw.

[sanibel sailor]

I think the deadrise is if you are mounting it perpendicular to the hull and depends on the angle of the beam. Mine is inside, in PVC pipe, steeper and works ok.

Have you tried it in your current setup?

[Mike OReilly]

Originally Posted by AZ-Oldguy

...Did you cut and glue your fairing block on to the hall yourself? And then drill a vertical hole through the whole thing? I am imagining a rather long extension bit on a 2 inch hole saw.

I was replacing an existing thru hull transducer, so didn’t have to cut a new hole. Under the the guidance of a fellow sailor who is far smarter than I, we bored out the existing hole to be a bit larger, then made a fibreglass tube that allowed the new transducer to just fit.

The Airmar transducer I bought came with a plastic fairing, but it didn’t fit very well, so again with the help of my friend, we built a whole new fairing out of closed cell and fibreglass. We epoxied it to the hull, and sealed it with multiple layers of glass.

It was not a small project, but the results have been perfect for going on eight years now. I have a near-vertical shooting transducer this way.

[AZ-Oldguy]

Originally Posted by sanibel sailor

I think the deadrise is if you are mounting it perpendicular to the hull and depends on the angle of the beam. Mine is inside, in PVC pipe, steeper and works ok.

Have you tried it in your current setup?

That is what I am leaning toward doing. But the transducers I have seen are all too big to fit in the existing well tube that I have in the hull. I will have to fabricate a new tube and fit it to the hull with some way to secure the transducer and keep the whole thing sealed.
What did you use to cement the PVC pipe to your hull?

[AZ-Oldguy]

Originally Posted by Mike OReilly

I was replacing an existing thru hull transducer, so didn’t have to cut a new hole. Under the the guidance of a fellow sailor who is far smarter than I, we bored out the existing hole to be a bit larger, then made a fibreglass tube that allowed the new transducer to just fit.

The Airmar transducer I bought came with a plastic fairing, but it didn’t fit very well, so again with the help of my friend, we built a whole new fairing out of closed cell and fibreglass. We epoxied it to the hull, and sealed it with multiple layers of glass.

It was not a small project, but the results have been perfect for going on eight years now. I have a near-vertical shooting transducer this way.

I like the idea of fabricating my own fairing around the base of the transducer. The one you linked to offers temperature and through the water speed as well. I haven't liked the idea of a large block disrupting flow over the hall, and thought that if one could just secure the transducer in place and then using fairing compound and microballoons or something , a couple of layers of glass, and minimize the amount of material protruding from the hall that would be pretty nice. It seems like the main objective would be to securely mount the transducer so that it wouldn't move, would stay vertical, and wouldn't leak.
It looks to me like the bronze housing of that transducer is permanently installed, but the working parts can be pulled out of the hole if they need servicing. Is that the case?
Glenn

[mlydon]

YES, you can reuse your well, expand as needed. Check out the instructions on a p79 - you are doing the same thing, only custom.....

They call for antifreeze instead it oil, but same concept.


Btw - if you invest $250 in a raymarine itc-5, you can use cheap analog transducers for speed, depth, and wind, instead of paying big bucks for nmea2000 ‘smart’ versions. The gizmo translates to nmea2000 and feeds that to your chart plotter, etc.

Matt

[Mike OReilly]

Originally Posted by AZ-Oldguy

I like the idea of fabricating my own fairing around the base of the transducer. The one you linked to offers temperature and through the water speed as well. I haven't liked the idea of a large block disrupting flow over the hall, and thought that if one could just secure the transducer in place and then using fairing compound and microballoons or something , a couple of layers of glass, and minimize the amount of material protruding from the hall that would be pretty nice. It seems like the main objective would be to securely mount the transducer so that it wouldn't move, would stay vertical, and wouldn't leak.
It looks to me like the bronze housing of that transducer is permanently installed, but the working parts can be pulled out of the hole if they need servicing. Is that the case?
Glenn

Yes, exactly. The actual transducer can be removed from the bronze housing. In theory it can even be done in the water, with the quick insertion of a blank. I’ve never tried this, but have removed the transducer.

I ended up building a fibreglass tube, in part b/c my hull is cored. I wanted to ensure the core was well sealed off. A solid hull wouldn’t present those challenges.

And yes, my transducer (the one I linked to) does record depth, speed and water temperature. I have a Tacktick system on my boat with all three data streams, so I ended up doing a raw wiring connection from the transducer. Luckily Airmar has the wiring diagrams online (at least, they did).

[sanibel sailor]

Attached my PVC to the hull with a generous goober of silicone. Water (Florida, no freeze) leaks or evaporates a bit over a year or so, so I have it arranged with a fill tube.

[AZ-Oldguy]

Originally Posted by mlydon

YES, you can reuse your well, expand as needed. Check out the instructions on a p79 - you are doing the same thing, only custom.....

They call for antifreeze instead it oil, but same concept.


Btw - if you invest $250 in a raymarine itc-5, you can use cheap analog transducers for speed, depth, and wind, instead of paying big bucks for nmea2000 ‘smart’ versions. The gizmo translates to nmea2000 and feeds that to your chart plotter, etc.

Matt

Thanks Matt, I had my hands on a p 79 just this afternoon. Actually I bought one when I originally purchased the chartplotter. and returned it when I couldn't figure out how to get the angles to work with my describe.
I have been leaning toward an in-Hull rather than a thu- hull installation because I didn't plan to haul out this spring. However I recently discovered that my packing gland needs to be repacked as it has reached the end of its adjustability and is still dripping. Since it looks like I'll be out of the water to do that job I might look seriously at installing the transducer with a fairing using the thru-hull.
Glenn

[chouliha]

Originally Posted by sanibel sailor

Attached my PVC to the hull with a generous goober of silicone. Water (Florida, no freeze) leaks or evaporates a bit over a year or so, so I have it arranged with a fill tube.

We did something similar with our fish finder. First we put the transducer in a baggie with fresh water and moved it around on the hull until we got a decent reading. Then just used a big glob of silicone to stick it to the hull. We often get reading in excess of a 100’. What we use it for besides determining depth is to see the bottom type. Especially to look for sandy section without any coral for anchoring

Good luck with your install

Chuck
Jacaranda