Author Topic: Advice about fitting depth sounders  (Read 13298 times)

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David

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Advice about fitting depth sounders
« on: 13 Jul 2011, 12:50 »
I am contemplating putting a depth sounder on my ply BR20 (cheap fishfinder) but am a bit unsure how to connect the transducer. I noticed Julian drilled a large hole in his outboard well but I am not as brave as that. I can't see any way down through the centre board well.  One option I thought was maybe to drill a hole in one of the plastic outboard well covers (the one closest to the rudder) held in by a bracket on the solid timber part. Has anyone fitted the transducer without major surgery

Thanks
David
Little Ripple

Julian Swindell

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Re: Advice about fitting depth sounders
« Reply #1 on: 13 Jul 2011, 13:00 »
I'm not brave! I agonised over it, but then decided that a 30mm hole right next to a huge great outboard well wasn't going to do anything nasty. It has worked exceptionally well and I wonder how I got on without it. The main benefit is when tacking up narrow channels. Now I can see when to push the tiller, rather than waiting to go aground. I just have a simple sounder and I think that works better for me than a fishfinder with it's "picture" of the sea bed. I think that might be distracting. But then again, I haven't tried it.

One point to note. When I drilled the hole, I rubbed epoxy all around the cut edge to keep the water out of the plywood.

You can read about it here:
http://daisygracebaycruiser20no1.blogspot.com/2011_02_01_archive.html
Julian Swindell
BayCruiser 20 Daisy Grace
http://jegsboat.wordpress.com/
Guillemot building blog
https://jegsguillemot.wordpress.com/

David

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Re: Advice about fitting depth sounders
« Reply #2 on: 13 Jul 2011, 13:05 »
Thanks Julian

It wasn't so much the location but exposing the timber to water if I wasn't careful enough, which I presume is why you coated the whole area with epoxy.

David

Graham W

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Re: Advice about fitting depth sounders
« Reply #3 on: 13 Jul 2011, 16:01 »
David,

The standard position for a Garmin transducer on a GRP Bayraider is mounted on a wooden block at the front bottom of the centreboard slot, so that it is just flush with the opening.
Graham
Gunter-rigged GRP BR20 #59 Turaco III

Tony

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Re: Advice about fitting depth sounders
« Reply #4 on: 14 Jul 2011, 02:13 »
My Cardigan Bay Lugger, Four Sisters,  is epoxy ply so no need to make holes for the transducer.
I’ve glued a cat food tin (one of the small, overpriced variety) with most of its base remove, to the bottom of the boat. All I do is slosh a little water in there and drop the transducer in – the cat food tin is just the right size – and switch on. The signal just pings straight through the hull and gives a nice clean trace on the screen, which wasn’t the case when I had the transducer mounted on the outboard well. It worked fine when the boat wasn’t moving but gave erratic readings at speeds over 2 knots. (I think that is caused by streams of air bubbles trapped under the hull or maybe just turbulent water flow around the transducer)
 I have not tried it at sea yet but on the reservoir its recording depth accurately (checked with a lead line) and picking up fish and bottom detail, too.  As I don’t need to look for a hole or cut a new one I can locate the transducer in the most convenient place, which is under the cabin sole, next to the lead ballast ( how I WISH I had water ballast) only about 2 feet back from the stem. I ve yet to find the ideal place for the screen. The cabin bulkhead  makes too good a backrest to be cluttered up with gadgets.  The unit is the Plastimo EchoFish 400, intended as a hand held device, which doesn’t make mounting it any easier,(I use Velcro S/A buttons) but it is at the cheaper end of the market – leastways, it was! Its price has gone up recently, it seems. (NB Avoid the cheaper Echofish 300. It only works on one frequency instead of two which is a Bad Thing, apparently.)  Being totally portable makes it handy if you fish from other peoples boats very often. The transducer has a removable float to hang from. Just chuck it in the water to find out just WHY you are catching nothing.
Photos to follow.

David

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Re: Advice about fitting depth sounders
« Reply #5 on: 14 Jul 2011, 05:23 »
My Cardigan Bay Lugger, Four Sisters,  is epoxy ply so no need to make holes for the transducer.
I’ve glued a cat food tin (one of the small, overpriced variety) with most of its base remove, to the bottom of the boat.

Thanks Tony thats very interesting and a bit of a suprise it works so well. All the details I have read about pinging through the hull say it wont work on ply (something to do with the air in plywood). I am not after any great accuracy or interested in fish details. I was getting a fishfinder as they are much cheaper than dedicated depth sounders and still give the depth.

David

Julian Swindell

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Re: Advice about fitting depth sounders
« Reply #6 on: 14 Jul 2011, 09:58 »
I'm also interested that you get a good signal through ply. All of the received knowledge is that it doesn't work, which is why I bored a hole. I have even read of people cutting a section of ply out and replacing it with a GRP laminate just so they can ping the transducer through it. Maybe with good, really solid marine ply it is OK. Seems to be in this case if you have checked the depth readings.

Or has Matt hoodwinked you and sold you a plastic boat...
Julian Swindell
BayCruiser 20 Daisy Grace
http://jegsboat.wordpress.com/
Guillemot building blog
https://jegsguillemot.wordpress.com/

Tony

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Re: Advice about fitting depth sounders
« Reply #7 on: 14 Jul 2011, 16:28 »
A good signal through ply? ...All of the received knowledge is that it doesn't work,....
Or has Matt hoodwinked you and sold you a plastic boat...

Hi, Folks.
Yeah, I was surprised it worked. Unbearably smug about it, too!
The handbook said “only through solid GRP”, which is why I spent ages faffing around with sticks, string, demountable brackets and various other constructions, trying to hang the damn thing over the side. I only found the truth when, in a fit of pique and frustration, I threw it onto the cockpit floor. It rolled the right way up in a pool of rainwater after a tack– only about 2mm deep –  and, some time later, I noticed the screen behaving like the picture on the box.
I actually assumed it had gone into Demo Mode at first! 

Im quite pleased that I don’t have to put it on E-Bay (along with all my other expensive mistakes) and that, after a bit of fiddling about – sorry, Experimentation – I now have it mounted more or less permanently with all the wiring tucked neatly out of harms way. 
Being a portable model brings the disadvantage that you can’t screw it down - but you can, by using Velcro pads, stick it to different places in the cockpit depending on whether you are sailing or fishing and you can remove it altogether to avoid theft in iffy moorings.
Just goes to show that, in some circumstances, you can’t beat trying stuff out for yourself to solve a problem. (Classic exception: Hmmm. I wonder if this electric heater will warm my bathwater?)

Lots of so-called experts are just guys that read a book once.

There you go. That’s an epigram, that is.

(As opposed to an epiglottis, Julian, which is what I would get punched up if I called ANY of Matt’s boats PLASTIC, in that disparaging tone, to his face  – even the GRP ones.)

JOKE:
Qu:     How can you tell a plastic BayRaider from a wooden one?
Ans:    From the sound they make when they bounce off a battleship.
(Well, I didn’t say it was a GOOD joke, did I?)

Simon Knight

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Re: Advice about fitting depth sounders
« Reply #8 on: 26 Jul 2011, 09:39 »
I have a combined chart plotter, fish finder, depth gauge, kitchen sink device which is great BUT it eats its battery.  So I am in the market for a depth only device that will last for days (weeks?) on a single charge or something that accepts dry cells. 

I was wondering what sort of power consumption do your devices use?
Simon Knight
BayRaider 20 No.27 - Carpe Diem
Shearwater Sailing Canoe - Eureka

Graham W

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Re: Advice about fitting depth sounders
« Reply #9 on: 26 Jul 2011, 15:29 »
My Garmin 556s kitchen sink device only lasted 2 days before it exhausted the battery (a Yuasa NP7-12).  So I uprated the battery to an NP18-12, which is still narrow enough to sit comfortably ahead of the centreboard case without getting in the way.  Now it should last at least 5 full days before recharge. I do not want to downgrade from the Garmin as the information that it provides is just too interesting!
Graham
Gunter-rigged GRP BR20 #59 Turaco III

Julian Swindell

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Re: Advice about fitting depth sounders
« Reply #10 on: 26 Jul 2011, 15:31 »
Hi Simon
Hope you survived the Raid! I have a Nasa Target depth sounder which claims to use only 25mA. It hasn't discharged my battery yet which is only recharged with a solar panel. Very clear and easy to read. It goes hay wire when the depth hits about 0.7m
Julian Swindell
BayCruiser 20 Daisy Grace
http://jegsboat.wordpress.com/
Guillemot building blog
https://jegsguillemot.wordpress.com/

Colin Morley

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Re: Advice about fitting depth sounders
« Reply #11 on: 26 Jul 2011, 21:46 »
Hi Graham,

I have had similar problems in my BR. I like my Garmin 556 but the present battery NP7-12 only lasts two days and always seems to give out just as I am coming back up a shallow winding river. So i liked the idea of a battery that can last 5 days. I see the NP18-12 is a bit longer and wider that the NP7-12. Did you make a new support for it or did you find it fits the one already there?
I find it very frustrating to have to get the battery out from under the front cross seat especially when i have lower the boom, spar and mast and so it is almost impossible to get it out easily. Have you thought of putting it in a different position?

Any advice welcome

Colin
Colin
BR James Caird

Graham W

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Re: Advice about fitting depth sounders
« Reply #12 on: 26 Jul 2011, 22:56 »
Hi Graham,

I have had similar problems in my BR. I like my Garmin 556 but the present battery NP7-12 only lasts two days and always seems to give out just as I am coming back up a shallow winding river. So i liked the idea of a battery that can last 5 days. I see the NP18-12 is a bit longer and wider that the NP7-12. Did you make a new support for it or did you find it fits the one already there?
I find it very frustrating to have to get the battery out from under the front cross seat especially when i have lower the boom, spar and mast and so it is almost impossible to get it out easily. Have you thought of putting it in a different position?

Any advice welcome

Colin

I had to make a new wooden support because the NP18-12 is slightly wider and a lot longer and taller than the NP7-12.  I charge it in situ using Ctek Comfort Connectors (ring terminal from the battery to male connector to female connector or maybe vice versa), so I have no problem with the position. Just unplug the battery from the circuit and plug it in to the charger instead.  Simples!
Graham
Gunter-rigged GRP BR20 #59 Turaco III