Question for those who know about these things.
Depth transducer, mounted in hull in front of keel in a 26; would it be 0 degree tilt, or 12, or 20?
Hull is not near, and thinking about ordering soon and replacing electronics in the spring before launch.
Anyone willing to impart hard-earned knowledge?
Thanks;
JohnS NS26C 046 lying hours away in Bath, ON.
On our 26 we cannot access the area ini front of the keel. our in hull transducer is off to the port side in front of the cabin bulkhead under the forward berth. I did not measure because we just used the transom mount transducer and just pressed it into a ed of toilet bowl wax. So far still good. I would guess that the angle is closer to 12º than 20.
Tim in STL
White O’morn NS26U #216
Harbor Point Yacht Club
West Alton, MO
John,
Tim’s answer is based on a 26U. I see from your signature that you have a 26C, which has the depthsounder and transducers located a bit differently. If you have the version of the manual downloadable from the Nonsuch.org website, the location is diagrammed on the 61st page.
Assuming yours are located as shown in the manual, which matches what was on my 26C when I had it, the depth sounder’s offset from center by less than a foot. I recall it as being pretty close to vertical, but I’m also relying on memory. I’d suggesting waiting to see if you get an answer from someone who has a 26C and can double check. However, if you don’t hear from anyone, my guess is you’re closer to accurate with a 0 setting than a 12 degree. Definitely not 20.
– Bob
Me Gusta
Nonsuch 26 U, #233
(formerly, Solar Wind, Nonsuch 26C #143)
Hi Tim, Bob, and anyone wanting to give advice;
Tim: Interesting… I did do a test with the Garmin GT54UHD transducer, resting on a ziploc bag containing water, in front of the keel last summer. I also did a test holding it taped to a boathook, and the admiral held it over the side.
Attached is one of the pictures I took. Does it look ok?? I have never peered at a newer than 20 years old chart plotter, so I’m not sure if it is ok or not. The boat was moored to the dock. Nobody’s seen the picture before, you guys/gals are the first. 
I know to attach the transducer inside of the hull some use silicone sealant, others use glycol in a sealed container, and some use toilet bowl wax.
Our chartplotter swings out into the companion way space; it swings back above the starboard Quarterberth when not in use. I did not want to have another wire dangling there on the swing arm - but maybe I’m being silly?? Another wire is not going to do much harm. When I did the test last summer, the new chartplotter had not been installed yet.
Maybe I’m over thinking this and I should just use the transducer I have.
Comments, advice, pats on the back more than welcome;
JohnS NS26C 046 Classic interior layout, lying in Bath, ON.
If the existing transducer does what you need, why bother? They do wear our after a while, at that point make the change.
John,
Sorry. I’m literally out of my depth on this one (pun noticed, although not originally intended).
In Marina del Rey and Santa Monica Bay, where I sail, the water’s reliably deep. I’ve had depth gauges on most of my boats, but never a plotter, and I can’t remember the last time I actually looked at what it said.
Sailing in Florida and suddenly realizing I had less than six inches of water under my keel was the last time it was an issue for me. But that was nearly 20 years ago.
My ability to contribute on this topic ended once it got past where the transducer’s located. As for placing the readout, I personally prefer to try to place things that require pushing buttons near the helm because I singlehand a lot. But, everyone’s different.
I slightly disagree with Thor on one point. He asks, if it ain’t broke, why fix it? I ask what’d be the most fun puttering I can do on the boat.
– Bob
Me Gusta
Nonsuch 26U #233
Thor;
If the existing transducer does what you need, why bother? They do wear our after a while, at that point make the change.
Fair question.
The existing instruments are at the end of life.
The old Standard Horizon chart plotter that was there when we purchased is not updatable chart-wise, and the existing charts in the thing have lots of “holes” in them, especially where channels narrow. It goes into “everything is blue and the shoreline is absolutely straight and there are no marks, as seen on the paper charts” mode. So, a new chart plotter was on the cards. The Admiral (and the registered boat owner) said so, and when she speaks about spending money on the boat, I listen.
The Chart Plotter I got last summer came as a package (on sale) with a transom hung “fish finder” transducer.
I was wondering if I could just use the same old Raymarine-Airmar transducer; found a US$230.00 interface box (Actisense DST-2), that spits out data in a standard, but still obsolete format, that the new chart plotter can read. (NMEA-0183)
A new Airmar transducer, that fits the same old hole in the hull, and puts out data in the new standard format (NMEA-2000) is $290.00 Canadian - $229.00 US, and no duty and border charges to pay. You’ll note that I can get the new transducer for a bit less than using the decades old one with the expensive interface box.
I don’t really need a “fish finder” and do not want to hang it off the transom of my 26, so I was thinking of just using the existing transducer hole.
Maybe I’ll just do as Tim in STL does, and remove the old transducer and fill the hole, and stick the fishfinder to the inside of the hull.
John,
You’re right on all of the above.
Nevertheless, I’ll unblushingly press on.
I vote for feet or fathoms when you tie the knots on the sounding line. I can handle the math to translate them into meters in my head, but somehow not to go in the other direction. (Raising the question, are Canadians just nicer or does it only seem that way because they’re preoccupied doing conversions in their heads?)
The line choice is complicated. You’re right about dyneema being non-stretch, but the slipperiness of the line interacts with your decisions about which knots to use. Definitely not single-braid – too prone to kinking, and not expensive enough.
You can save money and avoid the environmental discussion by using a paperweight from home, and in turn replace that with the old instruments.
I recommend animatedknots.com for advice on what knots to tie on the line.
– Bob
Me Gusta
Nonsuch 26U #233
John, frozen to the cradle in Bath. Next time do not stick your tongue to the cradle and you are less likely to become stuck.
The image in the photo looks right, if you are in about 7 metres of water, with a soft bottom (not commenting on your fitness level), the offset is adjusted correctly and there are no fish or obstructions below.
The depth transduce on La Reina is mounted in front of the keel and and does not require any tilt.
We anchored for about 15 years with out any problem. In the last 5 years we have hooked a rock the size of a small car, a tree that was at least 40 ft long ( the roots were still on the bottom when the top of the trunk broke the surface in 35 ft of water) and a section of an old boat. Each time required a diver to free the anchor rode because over the course of a few nights on the hook they had wrapped themselves securely around the obstructions. The imaged displayed by the fancy unit you show in the photo might have saved me from dropping the anchor over the obstructions.
The Nantucket Sound is a marvel of simple reliable technology, unfortunately designed manufactured and assembled in the U.S. of A. so the knots in it are tied in at the fathom marks. This unfortunately to the trained eye looks like it is at the 5 ft mark, a potentially significant difference. Based on past experience, I find it is helpful to have your charts and lead line (the Nantucket Sounder by the way is made of Bronze and therefore more salty and more environmentally friendly than lead) read in the same units to avoid confusion. It is also important to remember the Sounder does not have an offset for the keel depth. I prefer to work in ft since my charts were published prior to the invention of the metric system. The advantage of advantage of feet over fathoms is that you can tie the knots in at 10 foot intervals making the math much simpler when counting knots. Further more La Reina’s depth is measure in feet and inches not fathoms. This is convenient because the keel on La Reina is about 1/2 a knot deep as opposed to 8.33 fathoms.
A true Bluenoser would use tallow in the bottom of their Nantucket Sounder but since the First Sea Lord frowns on the the presence of that substance on board I have resorted to peanut butter (all evidence to the contrary I believe peanut butter was invented in Canada). I only use all natural peanut butter with no preservatives added. It is environmentally friendly, biodegradable and has a reasonable prospect of attracting salmon.
Mark Powers
