where to mount a fishfinder transducer

nice.diver · 05 February 2010, 04:59

I want to install a fishfinder on my transom. It will fit nicely within inches of the centerline, which is close to the outboard. I mostly care about the low speed reading, but would like it to work at speed also. WHERE is the turbulance from the motor at??? The boat is a flat bottom soft hull, no speed tubes, not ridged, just an inflatable keel. It may not work at speed because the transom "lifts" out of the water when the tubes get on top of the water. I plan to put it an inch from the scupper.

Question:: will the transducer work in front of the outboard (coupl inches to the side)

thank you

jyasaki · 05 February 2010, 16:32

My suggestion: Get a piece of wood about the height of your transom, and a C-clamp. Mount the xducer to the wood, clamp the wood to the transom, then start playing around with positions.

Most manufacturers say to mount the xducer off to one side to avoid the turbulence generated by the motor. Seems to me that most of that would be behind the motor, but, then again, I haven't really tested that.

As far as the transom lifting at speed, well, that's what you want. The transducer should be mounted approx even with the bottom of the boat, so at speed, the water should be rising coming off the aft the hull, keeping the xducer face in the water. Play around with height until you get the best performance for your setup.

jky

mirssant · 05 February 2010, 20:05

Hello

I install the transducer on my avon as far as posible from the motor just beside the tube and 1/2 Inch up from the botton of the transom and works very well at every speed, the transducer even at high speed keeps down the water. if you need i can send you some pics.

cheers

Sonar · 05 February 2010, 20:18

Maybe the best position for the position could be found in the user manual..

Or on a part of the boat that will produce no bubbles and smooth water.

nice.diver · 06 February 2010, 22:56

thank you
with the steel plate...the launch wheel studs... scupper drains...gussets of the tube to transom...only having 30 inches of transom to work with = there is only the one clean spot to mount.
thank you

mmgarrett · 18 February 2010, 07:14

Nice.diver, let me know how that works. I had bad luck with mounting it to my transom om my 14 footer. I ended up gluing it to the hull and it worked marginal at best when I was at speed.
mirssant, please post some pics if you can of how yours is mounted. I just got an 18 foot Achilles and will be mounting the transducer soon.
Thanks,
Matt

1ThOFA87 · 21 February 2010, 13:40

I have a silly question. How are you guys powering your fish finders? Not having an electrical system, are we restricted to portable fish finders? Or is there a way to use a stationary fish finder and power it somehow from a battery.

Flyguy · 21 February 2010, 23:32

Duplicate post

Flyguy · 21 February 2010, 23:34

I would do what Jyasaki suggests. I pack my zodiac away each trip so I use a portable setup.

As for power, use a 12V rechargeable battery in a watertight container. This one is a Aldis airtight food container, it lasts 2 trips before it needing recharging.

mmgarrett · 04 March 2010, 04:17

Quote:

Originally Posted by 1ThOFA87

I have a silly question. How are you guys powering your fish finders? Not having an electrical system, are we restricted to portable fish finders? Or is there a way to use a stationary fish finder and power it somehow from a battery.

On my old 14' I would power it with a small portable battery. I also use this on my kayak. On the new boat I will hook it up to a full size 12 volt battery. You can get these small batteries on the net or most electronic stores.

jyasaki · 04 March 2010, 16:28

My Achilles 14 had an electric start motor, so the battery was there anyway. I had a tractor and garden battery (basically a large motorcycle battery, I think) as the primary. Never had a problem with electrical supply.

For those without a charging circuit, you could do the same as the guys running trolling motors: use a removable battery (size would be up to you), and charge it remotely after a days use.

I would guess that, for, say, a GPS and a fishfinder, a small battery would give you a run time well beyond what you're normally going to need for a days use (multi-day trips may require a little more thought.)

jky

long1jon · 04 March 2010, 23:21

I seem to remember having an old lowrance and i'm almost sure, the transducer could be mounted on the inside of the hull. Anyone know if that's right. If so you could just hold it against the floor, simple's

Peter_C · 09 March 2010, 08:55

For future reference I did a lot of research on mounting my transducer for a sonar/depth finder unit. I have a Garmin 420 chart plotter/sounder, mounted on a Zodiac Futura MKII HD 4.2m. The conclusion, from an extensive information search, is the transducer needs to be mounted on the starboard side to stay out of the turbulence created on the port side by the propellers rotation. Mine is mounted fairly close to centerline, and below water line at planning speeds, which is also why it is closet to centerline, the lowest point of the hull.

The results of the depth sounder I am happy with. Once in a while it loses depth, but only for a few seconds in rough water, which is expected since the the entire boat will often come completely out of the water.

As to a battery, I do believe no matter what you decide to use the marine laws, at least in the US, require a marine approved battery box. I have a small Hawker Odyssey AGM mounted on the starboard side in the rear. Since I needed a battery to run my GPS might as well toss an electric starter on the motor, and love having to only hit a button for a second to fire up my outboard

mmgarrett · 18 March 2010, 19:16

Peter_C, How deep into the water is your transducer? I just mounted mine, like you explained, and the transducer going through the water shoots up a stream of water about 3-4 feet. Does that happen to yours? Could you add a pic of how you have yours mounted?
Here's some pics of mine:

Thanks,
Matt

nice.diver · 03 May 2010, 00:45

there should never be fear of a silly question

my boat has a 40 electric start so there is always a battery

Nos4r2 · 03 May 2010, 05:12

Quote:

Originally Posted by mmgarrett

Peter_C, How deep into the water is your transducer? I just mounted mine, like you explained, and the transducer going through the water shoots up a stream of water about 3-4 feet. Does that happen to yours? Could you add a pic of how you have yours mounted?
Here's some pics of mine:

Thanks,
Matt

I reckon you're a bit too deep with that as the mounting bracket is protruding into clear water below the hull. As long as the transducer body is in the water it should be fine.

chris123 · 03 May 2010, 10:12

Quote:

Originally Posted by mmgarrett

Peter_C, How deep into the water is your transducer? I just mounted mine, like you explained, and the transducer going through the water shoots up a stream of water about 3-4 feet. Does that happen to yours? Could you add a pic of how you have yours mounted?
Here's some pics of mine:

Thanks,
Matt

The blurb with my (not yet fitted) Garmin transom mount transducer specifies the bottom of the transducer should be 10mm below the bottom of the transom, so I think you could bring yours up a bit.

Cheers

Chris

jyasaki · 03 May 2010, 17:34

Quote:

Originally Posted by chris123

The blurb with my (not yet fitted) Garmin transom mount transducer specifies the bottom of the transducer should be 10mm below the bottom of the transom, so I think you could bring yours up a bit.

These instructions are written for hardboaters. That one, in particular, is saying that the transducer face needs to be in clean, smooth, non-aerated water, at a depth which is generally found when mounted that far below the transom. That will differ for boats that run at different attitudes or those that get lift from points other than the hull (as is apparently the case with whoever said their transom was mostly clear of the water at speed.) I'm not saying that their instructions aren't accurate or won't work; just that a) SIB's and RIB's don't always work the same as a glass center console, and b) the directions are a starting point for fine tuning.

My earlier suggestion to play with positioning and height prior to mounting stands.

jky

Northern Pike · 09 August 2011, 14:14

Hi, Found this old thread doing a search. Time to revive it.
I'm pondering a transducer installation on my Futura, but the speed tubes create a lot of turbulence in the area. Anyone out there had that problem/found a solution?
Thanks.

Peter_C · 11 August 2011, 19:25

Quote:

Originally Posted by mmgarrett

Peter_C, How deep into the water is your transducer? I just mounted mine, like you explained, and the transducer going through the water shoots up a stream of water about 3-4 feet. Does that happen to yours? Could you add a pic of how you have yours mounted?
Here's some pics of mine:

Thanks,
Matt

Your transducer is set too deep. I am in process of moving mine due to adding wheels, but I only had a small amount of water spray off the transducer, and never into the boat. Mine was mounted about 10mm below the transom.

Quote:

Originally Posted by Northern Pike

Hi, Found this old thread doing a search. Time to revive it.
I'm pondering a transducer installation on my Futura, but the speed tubes create a lot of turbulence in the area. Anyone out there had that problem/found a solution?
Thanks.

Never had a problem with the speed tubes, but I am moving mine out a couple of inches towards the starboard side to clear my wheel leg, so it might be a little bit before I get to test it. Having a depth sounder is really nice. A GPS is even nicer. Adding charts is the bomb!