In Hull transducer (Airmar) questions

[pablor]

Hi

I have an Airmar R199 with my furuno navneton a grady 360. I have two questions.

1. I bought the boat used. It is a grady 360 express with triple outboards. The transducer was installed midship very close to the centerline of the boat just about equidistant from the bow and stern (at the access panel under drain in front of the head). I seem to lose bottom quite often. Changing from 50 to 200 hz on the furuno and viceversa most times gets it back. I have a feeling that when the boat is on plane, the ducer is too far forward getting air, thus losing bottom. Should I move it back near the stern?

2. My network sounder is a furuno bff1. It goes up to 1kw. The transducer is rated to 2kw. What am I missing by not having a propely matched echosounder and ducer? is it just the ability to read bottom at depths > 1000 ft?

Thanks in advance

Pablo

 

[seasick]

It looks like Airmar wants the transducer towards the aft third of the boat and on center. Beleive me, I am no expert on this but I researched the Airmar site.
There are a few things to check. The transducer must be over solid fiberglass, not over wood or foam.
The transducer is also filed with oil. Check the oil level.
here is a link to the installation doc
http://airmartechnology.com/uploads/Ins ... 7%20ps.pdf

There is also a compatability doc. The Furino bff1 is nort specifically listed, the bff3 is. You probably will need to call Airmar to check if that is an issue.
Let us know how it goes.

 

[pablor]

thanks, I had been on the website before. I will call airmar for support....

 

[Capt Bill]

I agree that it may be too far forward. I would call Grady customer service. They will tell you exactly where the transducers should be located on the 360.

 

[gulfcart]

Don't get me going on this one!! I have a 2008 Grady 33 Express. I had a Furuno dealer installed a Furuno NavNet2 with the 1KW transducer. We called Grady to get a recommendation as to where the transducer should go. They recommended right where you have yours. Midship in the aft berth bilge. They installed it there. I would loose the bottom at 15 or less knots. Only way to get it to work at higher speed was to put trim tabs all the way down.
Finally after calling and installing a another brand unit with transon transducers so I could at least fish, they said cut a hole in the aft berth storage and mount it there. $400 later and a hole in my storage compartment ...no better. My dealer then mounted without the case about a foot further back(all the room we had there). Still no good.
Finally my dealer had another 33 in and was hired to install a 1kw transducer. He ended up installing it all the way in the aft bilge comapartment on the starboard side on the first lift. I had them move mine. That was another $300. Hopefully Grady learned at my expense. Works perfect now. Both frequencies at 25 knots plus. Now I have a back up unit also (HB Side Scan).

Unfortunetly no one took responsibility so I paid! My suggestion is try it back there before you "glue it" by just putting it in a water bag.

 

[Southern Hunter]

ducer

My transducer is located in the back half of my 305 and I have no problems at all picking up depths of 1500ft at cruising speed.

 

[NOTHING ELSE MATTERS]

My ducer is also under the aft cabin, but i don't have in hull on this boat, and i don't have a single problem. Maybe cause is not an inhull ?
On my previous boat( Bimini) i had an inhull and i installed it all the way aft to the port side and did not have a problem.

 

[pablor]

I was thinking about the aft bilge area where the generator is. I will check next time I am at the boat to make sure there is enough room there. I believe there is. Airmar also wants you to make sure there is no coring. It may be that.

I definetely lose all fishfinding abilities on rough seas or making sharp turns at high speeds. Even trolling sometimes I get nothing if the seas are a bit rough.

It should not be that hard to try it there. Cable routing is pretty easy. Thanks for all of the input. I will call grady as well. I had not thought of that. Airmar definetely recommends very very aft...

 

[jekyl]

I have a 1kw airmar with Furuno 585. I mounted the transducer in the centre aproximately 2ft from the transom in a high speed fairing block.
It reads perfectly at as much as 35 knots....we never go any faster ; on 200 and 50hz Generally the 200 is less sensitive to motor interference etc.

 

[RDCGrady]

I'm new to this forum and hope this is the right place for this response. I have a new 283 with a Furuno Sounder and matching transducer. The transducer is mounted on the flat area toward the stern of the boat and is supposedly the spot where Grady wants it mounted. The transducer is a thru hull not a shoot through. I often lose bottom after shifting into reverse but that is OK as I expect the turbulence to create a problem. The other night, I was running in flat seas at 43 mph and could not get a reading on bottom. Is there a solution to this problem? Do I need a different transducer or do I have to mount it somewhere else? Any help would be appreciated.

Thank you

 

[NOTHING ELSE MATTERS]

Did you try trimming the boat up or down to see if you have any reading?

 

[pablor]

Don't get me going on this one!! I have a 2008 Grady 33 Express. I had a Furuno dealer installed a Furuno NavNet2 with the 1KW transducer. We called Grady to get a recommendation as to where the transducer should go. They recommended right where you have yours. Midship in the aft berth bilge. They installed it there. I would loose the bottom at 15 or less knots. Only way to get it to work at higher speed was to put trim tabs all the way down.
Finally after calling and installing a another brand unit with transon transducers so I could at least fish, they said cut a hole in the aft berth storage and mount it there. $400 later and a hole in my storage compartment ...no better. My dealer then mounted without the case about a foot further back(all the room we had there). Still no good.
Finally my dealer had another 33 in and was hired to install a 1kw transducer. He ended up installing it all the way in the aft bilge comapartment on the starboard side on the first lift. I had them move mine. That was another $300. Hopefully Grady learned at my expense. Works perfect now. Both frequencies at 25 knots plus. Now I have a back up unit also (HB Side Scan).

Unfortunetly no one took responsibility so I paid! My suggestion is try it back there before you "glue it" by just putting it in a water bag.

I called Grady and they are still recommending the transducer in the aft berth bilge. They said the factory boat has it there and that the engineers say thats where it should go...

That being said I looked in the generator aft bilge compartment and it looks like a bit of surgery is required to get it in there...

GW said no coring or foam anywhere in the bottom of the hull...

 

[gulfcart]

All I can tell ya is make sure you try it before you epoxy in. I'll post the pictures of it in the aft bilge next week after the weekend on the boat. The box is (2) still epoxied in the aft berth bilge.. Couldn't get it out, ended up buying a new box to mount it in.....Twice..cause I didn't take my own advice!
I found this picture of the first and install in the aft berth bilge area before I moved it.

This is the second install ..which by the way..GW recommended. Had to cut a hole in the aft berth storage compartment.

Worked better but still would loose the bottom at speed. I don't have a picture where it is now but I will get one. Actually mounted it on the starboard side up on the first lift on the deadrise not right on the bottom. Works great.


sfc[/img]

 

[BobP]

RDC - did the problem just start or is it always that way?

 

[jekyl]

I have fitted 2 thru'hull transducers now as well as numerous transom mounts.; and the principles for all transducers are pretty much the same......clean water across the face, or bottom of the boat at all times.
Therefore any where as far aft as possible without interference from motors, skegs, strakes, keels, etc.
Anything that is going to cause bubbles is going to cause reading problems.
Mounting the transducer to far forward or to far out to the side will cause air under the face when the boat planes or rocks.
Look at any Grady's planing and there can be a lot of the hull out of the water.
An in hull transducer still requires clean water under the hull to read clearly all the time. As you have already noticed reversing will cause you to travel over your wake as well as change the whole dynamics of the position of the transducer.