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Transducer placement-above, flush or below hull bottom?

Old 09-28-2006, 08:20 PM
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Default Transducer placement-above, flush or below hull bottom?

I have a Garmin dual frequency transducer that was mounted by my dealer. I noticed that I am losing bottom image at anything above cruising speed. I was wondering if it has to do with the height of my transducer. It is currently about an inch below the bottom of the boat. So I was wondering if it should be as flush to the bottom as possible or maybe even above? Of course my transducer directions didn't make it back from the dealer. Thanks for your help. Greg
Old 09-28-2006, 10:58 PM
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Default Re: Transducer placement-above, flush or below hull bottom?

Most are about 5mm below the hull. Have you tried the Garmin website the manual could be on there.?
Old 09-29-2006, 09:47 AM
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Default Re: Transducer placement-above, flush or below hull bottom?

Transducer placement should meet all of the following requirements:

Below the hull
Nothing but smooth hull ahead of mounting location
Outside a certain diameter of the porp arc


I'm sure there are others, but these main points will insure that the ducer has clean water to shoot through. Placement is tricky but the right person can get it right for you. I did mine with the above factors in mind and I can mark a school of bait at 4 knots or 40 knots, no problem. The only time I lose bottom is when I put the motor in reverse, which is unavoidable.
Old 09-29-2006, 01:12 PM
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Default RE: Transducer placement-above, flush or below hull bottom?

Thanks for the info. I'll check for those things. Greg
Old 10-01-2006, 05:19 PM
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Default Re: Transducer placement-above, flush or below hull bottom?

Try tilting the transducer slightly forward. I think you can go as much as 10 degrees without getting a bad reading. If it is perfectly level it could be creating its own turbulance. There is a good article on this somewhere, I will see if I can find it and post it.
Old 10-04-2006, 11:11 AM
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Default Re: Transducer placement-above, flush or below hull bottom?

If you are losing bottom, tilt the back of the transducer down one click. If that doesn't do it, go down another click, etc. You need a good flow against the bottom of the transducer. If the back is tilted up, and sometimes when perfectly parallel, the water flow against the bottom of the transducer is not consistent.
Old 10-06-2006, 08:15 PM
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Default Re: Transducer placement-above, flush or below hull bottom?

An inch below the surface sounds a bit low. The 'ducer shouldn't be in the water below it's centerline, looking from the side. Clicking the back down a little should help, too. Sometimes, due to a strake, you have to move it around a little to get a clean image.

For just this reason, I highly recommend installing a starboard or nylon plate to the back of your boat and siliconing it in place. That way, you are not drilling the back of your boat every time you move the 'ducer.


Hope you get it to work right. You should, if you play around with it.

-TH
Old 10-07-2006, 10:02 PM
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Default RE: Transducer placement-above, flush or below hull bottom?

this is hard to explain but if you have a balsa core or cold molded boat not only drill through but out like a ring inside the hole fill that diameter with 5200. a wise mechanic tought me that. think about and you will understand why its styronger and better for the hull.
Old 10-07-2006, 10:16 PM
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Default RE: Transducer placement-above, flush or below hull bottom?

sorry guys, thought you were mounting a through hull ducer, I highly recommend BTW. but find out if your transom is wood, poured ceramic, whatever and if you are going the cheep way mount it (it says in the manual) but its usually 10" before the chine or right before first strake. dont pay to do it, moast people get too nervous drilling holes in their boat. make sure to go shallower than recommended and use 5200 as a back up. and dont drill a hole for the wire .I RECOMMEND suckingit up and go through hull you will thank me but i am a hard core fisherman who use make money doing it. i have seen mounting brackets fabricated so as not to drill in the transom. all hulls are different and have different weights thus buoyancy, so mounting a ducer and having air on it at 5 knots would suck.[img]../jscripts/tiny_mce/plugins/emotions/images/smiley-surprised.gif[/img]
Old 10-09-2006, 11:49 PM
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Default Re: Transducer placement-above, flush or below hull bottom?

That low will produce a lot of drag and expose it to hits from trash. 1/4" below the center part (deep) is plenty low, Tilt it so its flat shoothing a little forward when cruising.

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