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Hi,

Where is the best place for a depth sounder transducer?

I am replacing my depth sounder as it has become unreliable. I previously mounted the transducer inside the hull, on the centreline about 300mm in front of the mast. I was only able to read depths up to 6m, possibly due to the thickness of the fibreglass, and its shape, at this location.

I want to keep the transducer within the hull. I considered the bottom of the keel sump but as the manufacturer says the depth sounder will only work down to 0.8m, it would not read when I am in water shallower than 2.1m. I think a location about 500mm below the surface would be ideal.

I would be interested in the locations used by other people and whether they still get readings when heeled hard.

The attached photo may explain why I want to improve my set up.

Steve

I've got mine located just in front of the main forward bulkhead. It's under the starboard side of the v berth, tucked right in next to what looks like a longitudinal stringer and the base of the bulkhead. The best way to locate a good position is to seal the transducer in a plastic bag filled with water, then place the bag, with the transducer in it on the inside of the hull. Turn on your sounder and you should get a reading. Take the boat for a sail, with the temporary set up to see that you get close to what your charts say is the actual depth, give or take a little for the distance below the waterline and the sea state. Check it while stationary again and if it reads correctly, you're good to mount it permanently.

Mine is embedded in a puddle of epoxy. It's been there for 7 years now, and works well. It's important to make sure the epoxy, or what ever glue you use has no bubbles in it, as this will impair the "ping" function.

With mine, it's far enough forward to give me warning of a rising sea bed, but it does read a little differently depending on whether I'm on a port or starboard tack. Don't forget to set the depth alarm to at least a metre deeper than your draft, no point in having the thing go off after you hit bottom..... ahem.... as one of us may have done once or twice when coming in to his mooring in Careel Bay, not mentioning any names ahem....

Steve,

I see you do not dive, but that's a bit of a drastic way to inspect your bottom

I have my sounder head located just behind the cabin door to the cockpit.
It's not an ideal location but only happened when I had two sounders.
The ideal location is under the sink port side.

Remember if you use silicone to seat the transducer you should roll it into its final location to prevent bubbles in the silicone.

Thanks for the feedback Michael and Phillip. I'll try near the forward bulkhead.

We went aground at the top of a king tide. We were flying the kite and by the time we got that down we were too firmly aground to get off again. The next high tide was lower so we had to wait 24 hours to get afloat again. We had only gone out for a day sail but fortunately had our lunch and some biscuits aboard.

Hi Steve,
What type of sounder (model) did you go with?
Cheers,
Andrew

Hi Andrew,

I bought a NASA Marine Clipper depth sounder. I wanted a depth sounder with a load alarm buzzer so I would hear it above my noisy outboard. The Clipper has an external buzzer which looked in the advertising photos to be the same size as my old buzzer which I knew was loud enough. However, now the Clipper has arrived I find the buzzer is about a tenth of the size of the old one, so I am not sure that I have achieved my objective. I am locked down in Victoria so I cannot get to my boat to test it.
The Clipper design is decades old. Some modern fish finders are cheaper but I wanted the large display of the Clipper, and the external buzzer.

Steve