garmin in hull placement

[OBXTucker]

I just installed a new Garmin/Airmar M260 in the forward bilge if our LRC. Put it in the center on the bottom because it was level down there.

Unfortunately, I'm not getting a signal and starting to second guess if this unit (1kw) will shoot thru the keel portion of the keel.

Has anyone else installed one in this manner?
Next will be to connect the Garmin 6212 to another tranducer and just dell it over the side to assure the sounder box is working properly (I'm pretty sure the box is fine though).

Thanks.

 

[Boatsb]

I just installed a new Garmin/Airmar M260 in the forward bilge if our LRC. Put it in the center on the bottom because it was level down there.

Unfortunately, I'm not getting a signal and starting to second guess if this unit (1kw) will shoot thru the keel portion of the keel.

Has anyone else installed one in this manner?
Next will be to connect the Garmin 6212 to another tranducer and just dell it over the side to assure the sounder box is working properly (I'm pretty sure the box is fine though).

Thanks.

You can't shoot thriugh composites. There are too many layers. The right transducer and mount will take up the issue with the angle

 

[GJH]

The 260 is an extremely powerful shoot through, it will deliver great results once installed correctly. You have a very deep keel. You need to mount it away from the keel in a place where there will be minimum water disturbance near by. No place where there isn't anything but solid glass beneath it. Airmar prints pretty detailed instructions, didn't yours come with them? If not, you can download them I think. Also there is a guy on the THT Electronics forum that specializes in transducers and he is very helpful.

I have, via a PO their least expensive shoot through, the P79 and it works fine despite being in a not ideal location (near the AV intake). I hope to upgrade to a 260 someday, but since I only need depth and rudimentary bottom contour on occasion, it is not high on The List mine is hooked into a Furuno blackbox fish finder.

 

[Avenger]

Portions of the keel in my, and probably most other Hatterii, are foam cored. You need a solid material to shoot through.

 

[lumina]

Hi All,

Scrod......thats really interesting.....I've been told many many times by folks here on the forum that our sides, hulls and keels are solid...

If portions of the keel are foam cored it changes "current beliefs" considerably....

 

[Avenger]

I promise you mine is cored. I've seen it with my own two eyeballs, and have pieces to prove it. I can't say for certain that every one is, or how extensively, but they definitely used foam in some places.

 

[Boatsb]

I promise you mine is cored. I've seen it with my own two eyeballs, and have pieces to prove it. I can't say for certain that every one is, or how extensively, but they definitely used foam in some places.

No such thing as a solid hatt keel. the all are foam filled and then capped but too many have cracked and needed repairs.

 

[OBXTucker]

I'm definitely confused now....
I have a section of the hull, just above the keel that was recently removed for my bow thruster. It's solid glass.
So what's being said here is that BELOW this is cored??
I find that hard to believe.

Where's Roger when we need him?

 

[Boatsb]

Depending where it is the keel is anywhere from 2inches to 2 feet deep. In the bow it is very small and probably has no foam up that far forward.

 

[OBXTucker]

Portions of the keel in my, and probably most other Hatterii, are foam cored. You need a solid material to shoot through.

From the authoritative horses mouth (Steve):

"Hatteras LRC's were 100% glass. No core material. They only tried coring on a couple of convertibles (below the waterline) back then - and quickly realized it wasn't the right thing to do."

 

[GJH]

Including the keel?

 

[Boatsb]

OK Let me explain it differently.

The keel is 100 % glass and the area in which it drops well below the hull is open. Hatteras filled that hole with a similar material to what they used to make the stringers so they could put a cap over it and not have a deep inaccessible area only a few inches wide by the length of the boat.

It may not qualify as a core but it is filled with foam.

 

[Avenger]

What Scott said. I think you're misreading what Steve is saying. My hull itself is not cored. The keel has a foam core. It is not solid glass through and through.

Here's a pic of exploratory surgury that was done prior to repairing a leaking keel. That white stuff is foam:

 

[OBXTucker]

OK, it's obvious I didn't communicate well here - so I'll try again.

The In-Hull transducer I mounted went in the forward bilge, under the forward stateroom. It's about 10-12' back from the bow. In this area, it hull sides don't meet as a "v", but rather flatten out creating a level area. This is where I decided to mount it - since it eliminated the need to cut the tank at a 45 degree angle and mount it on the side of the hull facing down.

My assumption was the anything on the bottom of the boat is considered the keel - when in reality the keel is a seperate component. My apologies for the confusion....

All of this said, considering where I placed the unit, I'm going to continue under the assumption that it's solid glass beneath the transducer.

 

[Boatsb]

If its a foot off the center line that's correct. Its as solid as can be. By the way there is no need to cut the mounting tube. We get them where they are adjustable through a range.


FWIW I hate shooting through the hull. It's always more accurate with the through hull versions.

 

[GJH]

Probably best you consult with Airmar. All I can say is my wimpy P79 shoots through just fine.

 

[Colwyn D]

OBX, the flat area on the centerline that is so convenient to mount the transducer on is the top of the keel. This is either a quite thick section of 'glass or, if further back, it is layer of glass closing off the keel cavity which was filled with foam. This cavity was left after laying up your hull in the mold. The hull sides continue down to the bottom of the keel making a solid skin or laminate. This is a solid hull, no coring. What was left was a deep pocket, about 4" wide, along the centerline of your hull. All sorts of crap would accumulate here over time so it is filled with foam and skinned over.
Your transducer will shoot through a solid laminate that has the sea directly on the other side. The laminate you have mounted to is likely to be above the foam filling the keel void.
I hope this does not confuse things more and good luck with your project.