through-hull transducer

[Sofa King]

does anyone run one?
how are they?

[Smiley]

I am not using a true through-hull transducer, but something similar:

For 15 years now my fibreglass boat has had the transducer glued inside the bilge area. Google how to do it, just ensure there no bubbles in the epoxy. It is an easy mount to do.
I love not having to run a wire down the transom, and also love not having to drill holes for the mounting bracket screws. Also love never having to wonder if some debris has bumped the transducer.
For the past 2 years my dad and I have used the exact same sounder / transducer units, we can't tell that my internal mount is ANY different that his external mount. In other words, shooting through fibreglass has no visible effects on performance.

[bigdogeh]

I have one. it works with a furuno sounder... fairly straight forward. what type of boat do you have? think lots of people have them and they work fine.

[Sofa King]

a 24' sunrunner.
there isn't a lot of room on the transom.
it's mounted there now, but always seems to have hiccups.
large trim-tabs on the outer sides and the inboard motor taking a lot of room in the centre.
through-hull would be the cat's-ass, never having to wonder if weeds have caught on it, etc.

[bigdogeh]

a 24' sunrunner.
there isn't a lot of room on the transom.
it's mounted there now, but always seems to have hiccups.
large trim-tabs on the outer sides and the inboard motor taking a lot of room in the centre.
through-hull would be the cat's-ass, never having to wonder if weeds have caught on it, etc.

You should go for it then. If you don't want to go with a true thru hull, maybe get one like smiley mentioned... then you don't actually have to drill through the hull... just glass or epoxy it in. but I like the actual transducer that actually goes through the hull myself.

[Phila]

Hi Sk,

My boat and setup is similar to what you describe.

I am recently retired from the sonar biz and have just installed and tested a "shoot-through" transducer on my fibreglass hull. Some similarities to your situation including a 20 ft fibreglass hull. My second transducer on the boat is a transom mount. Both are dual frequency 50/200 kHz transducers. Ran them both last week for comparison. There is a noticeable loss of resolution on the shoot through, but not significant if your objective is to determine depth or large schools of fish. "Shoot through" transducers are Not the best choice for looking at schools of bait, fish just off the bottom and so on because of the lower resolution.

Considering frequencies, a transducer at 50 kHz frequency with a wide angle (cone) would be a better choice to determine depth while running. My through hull transducer will be run at 50 kHz for running/travelling and as a back up, since floating debris in the Fraser seems to hit and tip up my transom mounted transducer too frequently, leaving me without accurate depth info until I can push the transom mount TDX back down and lock it.

For transducer mounts, a through hull mounted transducer mounted forward of the transom and away from turbulence caused by keel protrusions, strakes, intakes etc. will give you better performance than a "shoot-through" transducer. Downside is that impacts to the transducer can cause expensive damage and in some cases, leaks. Trailering your boat can result in impacts to an exposed transducer from bunks or rollers when loading. Hitting floating chunks of wood at speed can also cause damage. Assuming your boat has a planing hull, you are limited to how far forward you can mount it. In the case of displacement hulls transducers would preferably be mounted in the forward third of the hull length.

Transom mounted transducers are more subject to interference from bubbles, particularly when operating in reverse. Most are designed to swing up on impact to avoid serious damage. The standard issue Lowrance transducers are this type.

Airmar makes a wide range of transducers compatible with Lowrance, Garmin and Furuno sonars. Worth a look at their site. Airmar has some low priced transducers that perform very well, such as the P66 (transom mount) and P79 (shoot through). Good tech support.


hope this is useful to you.

[bigdogeh]

can vouch for airmar also...

good post Phila!

[Fosey]

I have A aluminum boat, the transducer is mounted on the transom. The depth sounder does not work when I am running and the tech said to get a thru hull transducer. I was afraid to go with the through hull but might look into it after reading this. Any recommendations, I have A Furuno depth sounder.

[Vladimir Poutine]

I have A aluminum boat, the transducer is mounted on the transom. The depth sounder does not work when I am running and the tech said to get a thru hull transducer. I was afraid to go with the through hull but might look into it after reading this. Any recommendations, I have A Furuno depth sounder.

Sounds like a fix that doesn't need fixing. The problem you are having is generally due to incorrect position. You didn't say how big your boat is but if you trailer it, or if you ever drag it up on a beach you are asking for trouble with a thru hull. Try this link. It's for your brand.

https://www.furunousa.com/.../FurunoTransducerGuide-LR.pdf

[bigdogeh]

Hi fosey, I'm sure some guys will come out with some recommendations here... but have you tried a search at sportfishingbc.com ? those guys are really into this stuff. just found a thread that might be helpful on where not to instal a through hull if you are thinking of going that route. but alot of info there...

http://www.sportfishingbc.com/forum/showthread.php?25859-SCREEN-SHOTS-OF-FURUNO-587-WITH-NEW-1-kw-X-DUCER&highlight=aluminum+hull+transducer

[Edzzed]

I fiber glassed a transducer in my boat once. It worked and depth was quite accurate. I mounted it about 8 feet from the bow on an 18ft boat. If I had another fiberglass boat, I would do it again.

[Phila]

Some good threads on The Hull Truth on this subject.