Installing in Hull Depth Transducer

jsalley · Nov 26, 2016

I'd suggest sending an email to Warren Pandy at Catalina Yachts, with a precise location for where you want to do the install. The factory is pretty good about getting answers to these sort of questions - one of the advantages of having a manufacturer that's still in business.

marchem · Nov 26, 2016

If you've already got the transducer you can fill a baggie with water, and set the transducer on top of it in various locations and see how well it works.

You shouldn't use epoxy or 5200 to mount it, just in case you decide to (re)move it later.

Capt jgw · Nov 26, 2016

I've done it a couple times like Marchem said. Have to be in the water of course, but that's one of the reasons for going in hull. I used a big blob of clear silicone to stick it down. A long as there are no bubbles in the silicone it works well.

HMT2 · Nov 26, 2016

Used the Ziplock trick to find the best location for mine. It worked great. You need to fill the puck with some kind of liquid when you set it permanently I use non-txic marine antifreeze. It's been about five years and I've had to refill it three times.

Charlie98117 · Nov 26, 2016

buddybear said:
I am a little concerned with getting the transducer cable through the tubing at the pedestal.

Yes, when I moved everything to the helm I had to upgrade to the 1-1/4" dia pedestal to fit all the cables.

HMT2 · Nov 26, 2016

I just did an auto pilot install Garmin makes a field installable connector. If necessary you can cut the end off a NMEA 2k cable and install the field installable connector. It's pretty easy if you have some strong reading glasses!

marchem · Sep 1, 2018

buddybear said:
Thanks for all of the replies, I did send an email to Catalina Yachts to see if they could give me an idea of the hull thickness. I can buy the transducer from Garmin factory direct and have 30 days to return it. I think I will go that route to see if it will work, I am a little concerned with getting the transducer cable through the tubing at the pedestal.

How did this turn out? I'm looking at doing the same thing on our C310, but with the Raymarine version going to the e7D. Also not sure I can get the cable up the pedestal, but I'm confident I can cut/splice the cable if I need to. None of the manufacturers recommend doing that, but if you're careful and keep the shield intact it's not that tough.

marchem · Sep 1, 2018

buddybear said:
It worked great, I had to splice the cable to get it through the tubing. Mine was a Garmin 441S which had 3 wires and there was no shield. I used the silicone suggested which was GE, I think that is important to make sure you have a good seal. I believe the liquid is non-toxic antifreeze which I got from a pool supply store. When I spoke to the company I bought the transducer from the tech said no problem just splice it.

Where did you end up putting it? If not in the v berth do you see any issues with being behind the keel?

LeslieTroyer · Sep 1, 2018

On my 36 I have one in Vberth and one under the galley sink - just a bit forward and to the port side of the companionway steps. Both work equally well.

Les

marchem · Sep 1, 2018

Are you only reading depth, or is it a “fish finder” with graphical display?

dziedzicmj · Sep 4, 2018

I installed an in-hull transducer from Garmin (actually, it is an Arimar 79) under the v-berth. Different boat, but similar hulls. The ziplock check works great; you can check where it would or would not work. The in-hull transducer comes with a mounting ring that is supposed to be glassed to the hull. it can be adjusted so the transducer is level (you don't want it to shoot sideways). Finding the correct position was the most time consuming task.
I believe that you would need an extension for the cable. The standard length would not reach from the helm to the v-berth.
You will need to cut a fairly large opening in the binnacle tube. And it would have to be oval - the connector does not bend well(;-). Btw. if you do that, don't drill; cut at an angle instead. Works substantially faster in SS.

marchem · Oct 1, 2018

Finally ran the cable yesterday. Tried to get it to follow the existing depth/speed/wind cables under the head, but couldn't find a way through, so switched sides by the engine cooling thru hull, then back to the stern and up and into the aft cabin. Pulled all of the existing wiring out of the steering pedestal tube. Discovered that the connector on the transducer is just over 0.75", and the ID of the tubing is 0.75". So there's no way it would go up the tubing or ever come out at the top. Reran all of the wiring I had just removed (aargh!!). Managed to get the new cable to go down the tubing; waited until that last cable until I remembered I had some wiring pulling lube-should have been using it all along, What a difference it made!

Reconnected all the old wiring and amazingly everything still worked. Now I have to either solder/splice the new transducer cable together, or get an Airmar junction box (that's a thread I've got on Maine Sail's forum). I also had to cut the soldered connection I'd made previously between my below decks VHF and the RayMarine MFD (puts AIS info on the plotter screen). Need to decide if I will just resolder, or use a small terminal strip for that.

After all this work we'd better catch some fish next season, that's all my wife can say!!

marchem · Oct 1, 2018

buddybear said:
I spliced mine and it worked fine.

It seems to me that a well done solder/splice should be fine, and possibly better than a junction box; at least the shielding would be done more properly? I'll end up doing the joining inside the cover box in the aft berth, laying on my back squinting upwards. I probably should have picked a better place for the cut, but I was a little frustrated by then and just wanted to get done.