[PSUBS-MAILIST] Fw: DOSITS: Forward Looking Sonar

Fri May 15 10:49:30 EDT 2015

Alan,
My Humminbird transducer is epoxy potted. The Humminbird 360 is oil filled. I don't think it is nessesary to build a houseing for it. 
Thanks,
Scott Waters

Sent from my U.S. Cellular® Smartphone

-------- Original message --------
From: Alan James via Personal_Submersibles <personal_submersibles at psubs.org> 
Date:05/15/2015  2:41 AM  (GMT-08:00) 
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Cc:  
Subject: Re: [PSUBS-MAILIST] Fw: DOSITS: Forward Looking Sonar 

Have just come back from the local boat show after talking to a couple of
exhibitors about sonar / depth sounders.
I am still finding my way here. Was told I could mount a forward looking sonar inside
a fiberglass hull & would loose about 15% of my range as apposed to in water mounting.
They said the depth sounder worked better than the forward looking sonar through fiberglass.
Why not have a small view port type arrangement in the bottom or up front of the submarine
with a fiberglass plate in it. Then glue the transducer to that.
For a 3" diameter fiberglass plate .55" thick, I get a 4000ft crush depth. Safety factor of 4 for
plastics I think, so 500ft capable operating depth.
Quote from installation pdfs below......
As an alternative to transom mounting, it is possible on many
fiberglass-hulled boats to glue the transducer on the inside of
the boat hull. Since fiberglass has similar sonar
characteristics as water, the sonar signal can pass through
the boat hull with minimal loss. The hull of the boat must be
single layer construction (not double-hulled) Also, any air
trapped in the lamination of the fiberglass would prevent the
sonar signal from passing through.
Inside the hull installations require no holes be drilled into the
boat and through experimentation, high-speed operation
comparable to transom mounting can be achieved. Two-part
slow cure epoxy (not included) is required to glue the transducer in place.
......In-hull: Installed against the inside of the hull bottom, the in-hull transducer sends its signal through the hull. “Shoot through hull” transducers do not need direct water contact. They’re glued to the inside of the hull with silicone or epoxy. An in-hull transducer is a good choice for a trailered boat, a vessel with a stepped hull, and for other types of high performance hull designs, as there is no drag, hull penetration or potential for fouling. No integrated temperature sensor. Can be installed while boat is in the water. For deadrise angles up to 30 degrees. As with thru-hulls, the selected location should be aft and close to the centerline so that the transducer is in the water at all times.
In-hull transducers need solid fiberglass at the mounting location; no foam or plywood coring material, or air pockets. A typical 600W transducer can transmit through 1/2" to 5/8" (12-16mm) of fiberglass. To install inside a cored hull, find a location with no coring or remove the core material.
Alan

From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Monday, May 11, 2015 5:10 AM
Subject: Re: [PSUBS-MAILIST] Fw: DOSITS: Forward Looking Sonar

Looks really nice Hank, but couldn't find a price.
They are marketing to ship owners not recreational boat market.
Had looked at other 3d forward scanners & they are quite a bit more than
the Sinrad 2d.
Alan 

Sent from my iPad

> On 11/05/2015, at 12:26 am, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> 
> Alan,
> Check this system out, you probably have seen it.  This would be very nice to have.
> Hank
>> --- On Sun, 5/10/15, hank pronk <hankpronk at live.ca> wrote:
>> 
>> From: hank pronk <hankpronk at live.ca>
>> Subject: DOSITS: Forward Looking Sonar
>> To: "hanker_20032000 at yahoo.ca" <hanker_20032000 at yahoo.ca>
>> Received: Sunday, May 10, 2015, 8:25 AM
>> 
>> 
>> 
>> http://www.dosits.org/technology/locatingobjectsusingsonar/forwardlookingsonar/
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> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
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