Need help choosing a transducer.

Hi, I am installing new nav equipment on our boat. I have a garmin gsd 24 network sounder. My boat manufacturer says I need a 12 degree transducer. I already have a transducer through my hull that I would like to replace (not compatible with new equipment). Its about 2" in diameter. Maybe a little bigger.
Can anyone help me figure out which transducer I can use for the GSD 24 that will fit my boat?
I am getting conflicting information from the 'online' warehouse.
Thanks
Scott

Garmin can't answer this for you?

Capt.Bill11 said:

Garmin can't answer this for you?

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I havent called them. I figured I would ask the experts first.

I have the Garmin sonar. Garmin uses airmar transducers and has a chart to help you choose. I use a B60 20 degree with my GSD24.

bligh said:

I figured I would ask the experts first.

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Which is why you should call Garmin.

BTW this guy is a great source for transducers and knowledge thereof, and is a Garmin dealer:

travis.g@sbcglobal.net

The Hull Truth - Boating and Fishing Forum

Here is the B60 data

Garmin is the most reliable source for your inquiries. Believe me!

I have been looking at that chart. If I get one with the blue plastic block on it, do I just cut that plastic block down to match my deadrise and install the new unit?
Inside my boat , the existing transponder is mounted vertically and has wood and fiberglass that eliminates the deadrise so the nut can be tightened up properly. I am not really sure exactly what is going installed on the boat, but it looks a lot like the Airmar R99 in that catalog.

In most cases you can cut the block. But why not just use one of the model 60 units that mount almost flush?

Unless I am reading this wrong, the new transducer and it's nut should mount flat to the hull with no fairing block, the actual transducer is set at an angle inside the housing and the housing mounts flush to the hull. I have a B60 Lowrance 6 degree transducer installed in my Simrad MFD, the cutout was 2 3/8" as I recall. I drove a plug into the old 1" hole and drilled a new hole with a hole saw through the plug so the old hole was "inside" the new hole. That is a BIG hole A zero angle transducer would be what you are looking for if you fair it.

Capt.Bill11 said:

In most cases you can cut the block. But why not just use one of the model 60 units that mount almost flush?

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Well, I am not opposed to it, but wouldn't it be prudent to remove the existing transducer as well? If I do that, what is the best way to plug the old hole? I cant reuse the holes wince the inside of the hull is pre-faired with glass and wood for a fairing block style transducer.

Going through the garmin chart, the proper transducer to replace my existing transponder is a B258 or B260 (bronze vs SS). The issue that is causing me indecision and frustration is that the existing tranducer post is over 2" in diameter and the threaded posts on new airmar B258 and B260 are only 1.3" in diameter. It seems like retrofitting for this would risk water leaking in. I included a picture of my existing faring shim/block inside the ER.

AKDoug said:

Unless I am reading this wrong, the new transducer and it's nut should mount flat to the hull with no fairing block, the actual transducer is set at an angle inside the housing and the housing mounts flush to the hull. I have a B60 Lowrance 6 degree transducer installed in my Simrad MFD, the cutout was 2 3/8" as I recall. I drove a plug into the old 1" hole and drilled a new hole with a hole saw through the plug so the old hole was "inside" the new hole. That is a BIG hole A zero angle transducer would be what you are looking for if you fair it.

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Close, but my situation is the opposite. A smaller post with an existing larger hole.

caltexflanc said:

Which is why you should call Garmin.

BTW this guy is a great source for transducers and knowledge thereof, and is a Garmin dealer:

travis.g@sbcglobal.net

The Hull Truth - Boating and Fishing Forum

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I think this is more of an installation question as opposed to a garmin question. If you still think Travis is the best source for information, I will still contact him.

obthomas said:

I have the Garmin sonar. Garmin uses airmar transducers and has a chart to help you choose. I use a B60 20 degree with my GSD24.

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I can use the B60, but I will have to relocate the transducer and repair the hole from the old transducer.

bligh said:

Well, I am not opposed to it, but wouldn't it be prudent to remove the existing transducer as well? If I do that, what is the best way to plug the old hole? I cant reuse the holes wince the inside of the hull is pre-faired with glass and wood for a fairing block style transducer.

Going through the garmin chart, the proper transducer to replace my existing transponder is a B258 or B260 (bronze vs SS). The issue that is causing me indecision and frustration is that the existing tranducer post is over 2" in diameter and the threaded posts on new airmar B258 and B260 are only 1.3" in diameter. It seems like retrofitting for this would risk water leaking in. I included a picture of my existing faring shim/block inside the ER.

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The model 60 transducers use a 2" + hole I believe. And maybe it's just not apparent in the picture but I don't see any angle on that round fairing block?

Hi, Bill. thanks for the help. It's not apparent from the picture, but the fairing block inside is angled. Maybe I should just cut the old block out of the way and install the B60 in its place. What do you think?

Portuguese said:

Garmin is the most reliable source for your inquiries. Believe me!

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Not in Sydney Australia.

bligh said:

Hi, Bill. thanks for the help. It's not apparent from the picture, but the fairing block inside is angled. Maybe I should just cut the old block out of the way and install the B60 in its place. What do you think?

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I would think so. Are you going to do this in or out of the water?

Capt.Bill11 said:

I would think so. Are you going to do this in or out of the water?

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out of the water. I have a haul out scheduled in 3 weeks. Im not sure I would want to try it in the water. I'm sure my insurance company would like it done that way!

I've been in your situation before.

I have a pair of nice brand new Airmar transducers in my garage with Furuno pinnout cables on them for that exact reason. I bought them during my refit (wasnt near the boat) to see the large diameter.

First, your fairing blocks are probably just fine. No need to replace them.

All you need to do is find a compatible transducer of the same diameter.

I have used the airmar online listing several times to find compatible transducers.

If you cannot find one the same diameter then the correct method would be to fair out the old hole, and fill it in, then redrill the new hole. Thats a real PITA

I'd be inclined worst case to install a new transducer. You guys might laugh but I've also had great success with the professional grade shoot through the hull Airmar transducers. They are not cheap but they are way cheaper than paying for a fiberglass shop to do the job.

the regular shoot through the hull, pre angled transducer for my raymarine (which is an airmar) is less than $120.

when you haul next time...just fill in the old ducer hole (or not)...

my current ducer is a through hull that I'm shooting through the hull mounted in PVC and water...works fine....