in hull transducer - do they work ok?

[Parker9645]

I've had a transducer installed without a thru-the-hull. I glued, with 5200, a 4" piece of PVC, cut to fit the hull curve near the center line of the boat. Glued down the PVC and wait for it to dry. Filled the PVC with mineral oil deep enough to cover the transducer. Install the transducer inside the pipe, immersed in the oil. Cut a small slot at the top for the wire and put a PVC cap on the top of the pipe. Have had it installed over 15 years with no problem.

[NormanMartin]

I installed an inside the hull depth transducer from Hummingbird and it worked perfectly. Not expensive, either. Years later we got a Garmin system and I installed their transducer inside the hull with similar results.
Boat was a 1984 Aphrodite 101 with a thick fiberglass hull.

[merrydolphin]

Yes, they work. Installed one on my Cal 46 with thick solid glass hull.

First tried it with a plastic bag filled with water as per instructions. Once saw how it worked and properly installed with mineral oil.

I got a nice image of a whale 750 feet under me. And could pick up hard bottom at over 2000 feet. Never a problem.

[Donlin]

Properly installed, they work fine. I have had one wired to my Standard Horizon plotter for more than 8 years and there have been no issues.

[Jimmyhenry]

Brilliant. Nothing outside the hull to get fouled.

[rossdv8]

We have a "fishfinder" for depth instrument. I cut the bottom from a PVC electrical octagon box, siliconed this box to a flat spot on the hull, filled it with non-toxic antifreeze,

I used a fishfinder in both my last yachts. I used to sail 26 foot ex Quarter Ton racing yachts and lived in the Whitsundays, where we have a lot of shallow reef (rock and coral) and some nasty surprises.

I mounted them in stuff like Silicone Sealant, but it is 'crystal clear' and 'acrylic' if you apply it carefully. No bubbles and nothing really to interfere, so it is probably as good as trying to mount it in anti-freeze.

One of the yachts was trailable, and the hull ahead of the centreboard trunk where I mounted the transducer was pretty thick (as I discovered after the yacht was wrecked in a Cyclone), so I was a little concerned, but it turned out to be excellent and very accurate.
The other yacht was a normal keel boat and again, the hull was pretty thick where I mounted the transducer - just ahead of the keel (as I discovered when the yacht was wrecked in a cyclone).

Both yachts had traditional depth sounders originally, but the fishfinder was so much better and less hassle. I had the display mounted so it could sit in the companionway as the bottom section of a stormboard (easily viewed from the helm), or it could be sat inside where I could watch depths at anchor.

If I returned to sailing and had a yacht with a traditional depth sounder, I would still be fitting a fishfinder.

[Icarus]

Originally Posted by OzDean

Has anyone used one these "in hull" rather than "through hull" transducers? Saves making holes in the hull I guess! I have a 43' Jeanneau Sun Fast, current set Raymarine instruments (ST290 18 years old), I am not ready to buy a complete new set but need a depth sounder to go sailing. My plan would be to buy the Raymarine i40 with "in hull" transducer for about $450 AUD and mount the transducer about 1.5m forward of the current one or as far forward as I can. I will have to check hull thickness and angle. Then I would have a standalone depth sounder, can be a back up once I get a new system. Has anyone installed one of these in hull, do they work? The boat is on the hard at the moment so I could technically swap out the old transducer a new one, but launching tomorrow. Your thoughts? Thanks, Dean

Yes they work fine, I have a Garmin in hull depth sounder/fish finder.
Just make sure the mounting surface is free of flaky paint etc.

[Dooglas]

I have mounted inside the hull transducers in a mineral oil bath inside of a containor I fabricated out of PVC, and ones which I glued to the inside of the hull with polyester resin. Both worked fine. I have used vaseline to test the position of the transducer before permanent mounting. That also works fine and is a prudent first step. As others have commented, cored hulls will interfere with the beam.

[Grigory]

After correct installation - OK, no problem. (GRP hull, old, maybe near 1,5-2 cm thickness at bottom). If you will use glue, not any box with oil or another liquid, be aware on small air bubbles inside glue! If bubble exist, device cant work.
For example, dont use "fast-epoxy", better common use with low viscosity at first hours.
Better also to check place to install transduser (if GRP have some defects, air can be inside it). I made a small "bath" at the bottom with plasticine walls, put water into it and lowered the sensor into. OK! If it works, place is good.

[dalepo]

[QUOTE=Chotu;3454613]I was fearful of this approach for my boat. Foam cored hull. So there would be nothing between my tank ad that thin skin of fiberglass the bottom paint is rolled onto.

What's the best way to tell whether a part of the hull is foam cored vs solid?

[Lake-Effect]

Originally Posted by dalepo

I was fearful of this approach for my boat. Foam cored hull. So there would be nothing between my tank ad that thin skin of fiberglass the bottom paint is rolled onto.

What's the best way to tell whether a part of the hull is foam cored vs solid?

1. from other owners of the same boat, or from the manufacturer
2. try it. If the depth sounder works ok when the transducer is dangled into the water over the side, but not when the transducer is in a baggie of water and placed in a suitable location on the hull... you have a cored hull, or for some other hull reason it won't work.

[Group9]

Originally Posted by Parker9645

I've had a transducer installed without a thru-the-hull. I glued, with 5200, a 4" piece of PVC, cut to fit the hull curve near the center line of the boat. Glued down the PVC and wait for it to dry. Filled the PVC with mineral oil deep enough to cover the transducer. Install the transducer inside the pipe, immersed in the oil. Cut a small slot at the top for the wire and put a PVC cap on the top of the pipe. Have had it installed over 15 years with no problem.

Put one in the exact same way on a prior sailboat. Worked great.

[JRO]

Mine has been working perfectly for years.

[George_SD]

I run a cheap, low power CHRIP transducer in hull, mounted in a dolop of toilet seat wax. Works great, finds fish, goes to about 400ft.

[Group9]

Just put a new Garmin transducer in last night. I did the plastic bag full of water test, and then I made a little bottomless pool with a butter spread container cut for the angle of the hull and hot glued it in place.

Then I took some West System 610 epoxy ( the kind in the caulk tube) and squirted the entire tube into the butter cup pool, and then pushed the transducer into the epoxy. I watched it a few minutes to make sure it didn’t move, then checked the chart plotter.

Working perfectly 24 hours later so I guess I’m good. The temperature reading is even working, which I didn’t expect and it appears to be accurate to within a couple of degrees.

This was just a standard Garmin transom mount transducer.