In hull transducers

[bcharris101]

I have a 1976 2-22 ventura. I want to add some electronics, like a fishfinder. I was thinking of using an inhull transducer so that I would not have to drill any holes to the outside of the boat. Will such a tranducer work on this old of a boat and where should I place it. I presume some where infront of the keel, Does anyone know of any problems of using thes on this type of boat. I know new boats have a flat area to install it, I presume this boat will not have that.

[Duane Dunn, Allegro]

Your boat, all the non-water ballasted Mac's, are the easiest to install these in. You don't have to worry about avoiding the water tank cavities.

Install the transducer anywhere you can get easy access. The location must be below the water line, preferably as deep as possible. You want to shoot straight down, not angled to the side. Try to avoid directly beside the keel. You also want an area that will be bubble free (air is what messes up the transmission of the echo). This would put it as far forward as possible.

In my Venture 21 I mounted my puck up near the front of the keel slightly to one side and it worked fine. I purchased a transducer made for shoot through appllications which had a nice bevel on the bottom surface to match the hull contour. It was easy to just mix up a batch of epoxy and bed the transducer in it. Make sure you have no air bubbles in the the epoxy and no gaps between the transducer and the hull.

There are less permanent methods of mounting transducers. Some have used plumbers putty with success. Another way is to epoxy in a tube, fill the tube with water or oil, drop in the transducer and seal the top. You can also mount most transom style transducers by these methods as well. They are a little harder to adapt to what most likely is a angled hull surface.

[richandlori]

Mine was happily monted with plain old Silicon....and worked like a champ.

Welcome to the Site!

Rich Boren
S/V THIRD DAY
www.pearson365.com
><(((0>

[LOUIS B HOLUB]

My previous boat, a Mac 26S had the transducer installed by the dealer in the rear storage compartment, positioned flat on the floor with a generous amount of silicone. It worked so good, that I used the same installation idea in my Mac X, and installed the transducer on the flat floor under the galley with a bunch of silicone (being careful to avoid any bubbles). It works great. (We see fish and water depths perfectly).

[Currie]

My boat came with a Hummingbird, transom-mount (exterior) tranducer. It was installed, however, inside the hull with a lot of "goo" of some kind or another. It's doesn't work at all. I'm going to test the transducer outside of the boat to make sure it's working, but...is there a difference between an in-hull (i.e. not cut thru), and an exterior-mount tranducer? IOW- can an exterior trans be used inside the hull? Thanks!

~Bob

[parrothead]

Humminbird markets their basic model HDR 610 depth sounder with either a transom-mount transducer or an in-hull "puck" transducer. See
http://tiny.cc/YbOqq

Their maunal indicates that the transom-mount unit will work as an in-hull application, but the "puck" style comes with special slow-cure epoxy adhesive that is intended especially for that use [air bubbles trapped in regular epoxy - or any other adhesive medium - being a major source of sounder error].
I installed one of these "puck" style units in our last summer, under the rear berth, just outboard of the starboard ballast tube. It works very well below about 13 mph - but then defaults to a consistent reading of 6 feet -- perhaps being confused by air bubbles resulting from turbulence caused by the daggerboard opening? My major concerns about water depth are when operating well below 13 mph [either under sail, or under power in an anchorage/near shore], so I'll live with it. Doing it again, I'd go for a location farther from the centerline.

[Duane Dunn, Allegro]

The transom style can work just as well inside. It's really the installation that matters.

You must avoid any air between the transducer and the sea bottom. This obviously limits how and where it is installed. Most importantly in a X or M you have to make sure you are attaching it to the true hull bottom, not to the top of one of the many water ballast cavities. You should also avoid locations behind underwater apendages that may make bubbles in the water. Forward is usually better than aft. A location that comes out of the water when heeled during sailing would be bad as well.

If you are sure you have a good location with nothing but solid fiberglass you should be fine. You also want as dense a material as possible to bed the transducer in (with no bubbles). Epoxy is best, but very permanent, other materials may work. Keep in mind you need the material to transfer low frequency sound as clearly as possible. Soft materials may attenuate the signal.

[eric3a]

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[LOUIS B HOLUB]

Argh!
It's such a must around here that I will buy a new one tomorrow and mount inside so this thread is sure welcome!
Eric

A must around here indeed. Mine will read 1 and 2 feet in Clear Lake occasionally if I get out of the channel. And its not uncommon to hear the centerboard or engine bump something -- sometimes I think theyre lost Crab Traps.

Anyway, my transducer works great under the galley, flat on the floor (plenty of silicone with no bubbles). Readings of depth, and fish images, have worked well with this installation.

[eric3a]

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[LOUIS B HOLUB]

Thanks Louis; That'll save me from trying too many placement options.
Enjoyed the 35 knots gusts today on the windsurf!
Eric

I thought about you when I saw & heard all that wind today--I figured you'd be on (or in ) the water -- one way or another Bet you had loads of fun...

[eric3a]

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[LOUIS B HOLUB]

Thinking about the galley transducer location: I assume it's OK even on a heel? Wondering if on a good Std heel under sail the transducer would come out of the water?

Eric

A stiff port side wind actually may interfere with a depth reading (if the starboard side rail is in the water ). However, so far, I've had no problem. But, as you know, Im more of a fair weather sailor with my "X".
Another thing about the transducer, and using silicone, you can relocate it if a problem occurs.

Ive found most of the Bay as having good depths -- at least 10 ft. However, when Im near the shore, I always sail & motor conservatively because of shallows, and those doggonned Crab Traps...

[eric3a]

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[LOUIS B HOLUB]

Thanks Louis.

I rarley see 10 feet in my part of the world (towards Tabbs Bay/Cedar Bayou, Trinity Bay)!

I'm lucky when I can fully extend the centerboard in my bay.
Eric

That's one of several reasons I like my Mac. The shallow draft works so well in our area.
Incidentally, there is some good "birding" in shallows along the shores near Anahuac.