SV Shaula-transducer mount

Hi Dan, Had to ask you about your transducer mount in the engine compartment. Any problems with readings when heeled? Can you show us any pics? Any other advice about the mounting location or method? Really appreciate any input you offer. Thanks, Ray

Hi Ray,
I mounted the fishfinder transducer roughly aft of the port cockpit drain seacock in the engine compartment. It should have been placed lower, because it looses its signal when we heel very far on port tack resulting in that spot on the hull having air rather than water under it. Of course the lower it’s mounted, the steeper the curve of the hull, but I think it would still work OK. I made a little wood dam, stuck to the unpainted hull with a dab of poly sulfide, to contain the silicon. Although we don’t get the full range on the fishfinder, we get several hundred feet and that has seemed enough.

My original (about 1982-3?)inside mount was in the same area, a bit lower, but still not low enough to avoid the heeling problem. I epoxied a 4" PVC pipe to the hull, capped it with a PVC cap with a hole drilled in the top. The depthsounder’s hockey puck was mounted in the cap, rather than through the hull. I filled the pipe with mineral oil–I think based on some magazine article??? I could never stop the oil from leaking from the cap, so gave up on the pipe and went for the silicon blob, which someone had told me about. A friend recently told me he uses water instead of mineral oil and it works OK.

One of these years I’m going to remove the PVC pipe and move the blob down to a spot a bit below where the pipe is. I crawl back so I’m sitting with my back against the lazarette bulkhead. I don’t want to have to crawl over the transducer so need a clear crawl space. We cook and heat with kero and have a 6 gal tank mounted back there and we store stuff we don’t need very often above the tank.

We’re hauling out tomorrow but I’ll try to take a pic soon.
Dan Shaula

Thanks Dan, Appreciate the input. I’m really torn where and how to mount a transducer. currently thinking about a centerline mount forward of the ballast but looking for alternatives. Ray

I’m not sure I’d be comfortable with a transducer on the centerline
(through the keel). The full length of the keel is more susceptible to
impact (grounding and floating obstructions), and I wouldn’t want to
compromise that structure in any way or introduce a snag risk (fish nets
etc). My transducer is mounted under my galley sink. I had complete
freedom on choosing placement and just chose the location that seemed to
come closest to horizontal. My transducer is a resin mushroom mounted
through the hull. I did not use any block to try and make it more
vertical, and it’s far from vertical. The transducer came with a 1994 era
Ratheon Tridata unit. Nothing fancy. I think they’re all made by Airmar
regardless. There is slight difference between port and SB tack - maybe a
1-2 feet. But I’m rarely heeled in water where the 1-2 foot difference is
consequential. I’ve not had any regrets.

Regards,
Jeremy

On Mon, Apr 22, 2013 at 8:26 PM, BCC Forums bccforums@samlmorse.com wrote:

I’m not sure I’d be comfortable with a transducer on the centerline (through the keel). The full length of the keel is more susceptible to impact (grounding and floating obstructions), and I wouldn’t want to compromise that structure in any way or introduce a snag risk (fish nets etc). My transducer is mounted under my galley sink. I had complete freedom on choosing placement and just chose the location that seemed to come closest to horizontal. My transducer is a resin mushroom mounted through the hull. I did not use any block to try and make it more vertical, and it’s far from vertical. The transducer came with a 1994 era Ratheon Tridata unit. Nothing fancy. I think they’re all made by Airmar regardless. There is slight difference between port and SB tack - maybe a 1-2 feet. But I’m rarely heeled in water where the 1-2 foot difference is consequential. I’ve not had any regrets.

Regards,
Jeremy

If your purpose for the depthsounder is to measure the depth of the water you’ve just passed over, then placing the depthsounder aft would be logical.

If your purpose is to avoid grounding, to avoid closing a coral reef, or to alert you to a floating log or cargo container, then a traditional fishfinder depthsounder is not a good choice. Instead, you need a forward looking sonar, especially one that scans both vertically (to look for floating logs, containers, sandbanks, and coral reefs) and horizontally (to tell you which side of the channel has deeper water).

And then the mounting locations are limited - too far forward and it would be in aerated water.

With luck (meaning if my photo gets attached), you’ll see the tranducer of Z’s forward looking sonar. Pic comes as she was in the slings, about to be re-launched late in 2011.

Cheers

Bil

My interest is driven by having just removed an old, unused centerline mount transducer that was abandoned before we bought Whisper. This was a thru hull unit that was flush with the hull and had taken a few scrapes and hits. It gives the impression that the surrounding structure was strong enough that local weakness wasn’t an issue. The hull is 2"+ thick here. I am thinking of using that same location but using an in hull mount and would re-glass approx. 3/4 to 1 inch of hull. As far as a forward looking unit, I have to admit that thinking about that protrusion would scare the **** out of me in thin water. I envy you the asset but they don’t call me the “chicken of the sea” for nothing. I always appreciate the discussion and ideas that come from this board so thanks to everyone. Ray