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in-hull depth transducer in Centaur?

Posted: Sun Feb 28, 2016 1:21 am
by yankeedoodle
Has anyone used an in-hull depth transducer in a centaur? I'd like to stick one in a locker in the forepeak but I've never used one before.



Re: in-hull depth transducer in Centaur?

Posted: Sun Feb 28, 2016 11:16 am
by Jolly Roger

It has been years since I fitted a depth sounder, but I did use an in hull mounting on the last one about 25 years ago. Bascally this is a normal transducer that is fixed into a tube sealed to the hull. To ensure a good reading, the air space between the hull and the transducer is filled with, IIRC, parafin oil that came in the kit. No difference in working of the depth sounder between a through hull and a in hull mounting of the transducer. So you will be fine provided it is located in a suitable position on the hull.

Just remembered a funny story relating to an echo sounder. This was in the early 1970's on my father's racing yacht. As we were leaving the mooring, the echo sounder had stopped working. This was a problem as we were racing at Burnham on Crouch, a fast flowing river with lots of shallows. So racing without an echo sounder was a massive risk, especially when trying to cheat the strong tide. So my father was dropped ashore and he managed to buy a new echo sounder and only reached the boat a couple of minutes before the 10 minute gun was fired. Panic stations aboard to try and rig the new echo sounder up, it was not the same type so no simple just change over. It was wired direct to the battery and the transducer was taped to the end of a scrubbing brush - simple but it worked as we did not run aground that day! I have to admit it was not fun holding the scrubbing brush over the side whilst racing.

Re: in-hull depth transducer in Centaur?

Posted: Sun Feb 28, 2016 1:12 pm
by Uncle Albert
I Installed one in 2014 due to the expiry of my autohelm one of some 20 years. I have for too many holes in my hull for stuff (there are 2 redundant transducers through hull so did not want another!!)

The NASA one has worked fine and the installation was done the simplest way. Firstly I test sited it with a large slice of NEW bluetack, connected it up and ensured I had a good signal and that the thick layup did not influence it via any voids in the fibreglass etc.
For a final fix a really large dollop of silicon sealer was laid from a new tube of the stuff in the chosen spot and the transducer pressed into it. Do not stir the silicon about or massage it in any way as this can introduce airbubbles and that it not desirable. Check its still in place but dont 'test move it' for at least 48 hours to give the silicon time to go off totally.

My selected location is in in the locker next to the mast compression post and near the heads seacocks. Its reasonable flat there and I do not use that locker for storage so there is nothing to move about and dislodge it. Its also probably the thickest part of the hull layup.

Re: in-hull depth transducer in Centaur?

Posted: Tue Mar 22, 2016 12:14 am
by yankeedoodle
Belated thanks for the responses! Another job to add to the list.

Roger, if the in hull doesn't work, maybe I'll resort to your father's set-up.