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Fitting instruments

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Vidwatts says:

I'm taking Aeolus out of the water for a few months for a winter re-fit (having done little to her apart from lots of sailing since buying her from Malcolm last summer) and one of the things I'm thinking about is adding some instruments.

She has an old Seafarer 3 echo sounder which is fine, but can't be seen from the cockpit and I think a digital display would be handy. I also am planning a wind indicator and a speed log too. The depth and speed can be one unit, the wind would be separate. She has no instruments other than the Seafarer fitted currently.

My core concerns are:
- cost (don't want to spend a fortune)
- size of display: I'll need to find room for two panels somewhere visible
- holes in the hull: at the moment she has none, which is a source of reassurance: I'd need to drill one for the speed but can probably re-use the through-hull transducer from the Seafarer.
- cutting holes to fit the instrument displays in the cockpit
- wiring of electrics and associated power demands
- wind speed will mean taking the mast down to fit, I guess.

I've been looking at what's on the market and there's a big range in cost but seemingly little difference in basic functionality.

What can others recommend - and any advice on fitting is welcome.
(This would be by far the most ambitious thing I'll have attempted....)
9:23AM, 11 October 2010 PDT (permalink)

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blueachilles says:

We changed to a NASA Target log & depth after the first season with Blue. The depth transducer sits in a grp well thingy in the port saloon locker, in a pool of oil as per instructions; we used the same grp well as the previous set up, which I think was the same as your echo sounder. You can put in an offset for the depth from the transducer to the bottom of the keel.

The log needed a different size hole in the hull, and we had the boatyard do it - far too scary for diy!!

The old instruments fitted into 3-4" holes in the bulkhead in the cockpit. The NASA ones need only a 1" or so hole for wiring, and four screw holes, so we fitted a ply panel over the big holes, and drilled the relevant holes for the new instruments. A project for this year is to swap the ply for a piece of opaque perspex so we don't have to keep varnishing the ply.

The instruments work fine, except that the log paddlewheel gets clogged and we're too scared to take it out to clean when the boats in the water! Sometimes, you can loosen it, and turn it 180 degrees while the boat is moving, to free it.

Power demands: very little!

Wiring - simple.

Cost - see any boat magazine. NASA Target is the cheap & cheerful one.

We have sailed boats with a wind indicator, and Di in particular finds it really useful when beating. It would mean taking the mast down, or climbing it, and they're not cheap. So we'll manage without; might rethink if we have to take the mast down for any reason.

Hope this helps!

Rod
107 months ago (permalink)

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Mike A1 says:

I've also fitted the NASA Target depth and log. The depth sounder is fine. Like me you probably have a purpose made hole just forward of the keel. It might be possible to use the Seafarer transducer - NASA may know - but I changed mine and had to enlarge the hole slightly for it to fit.

The log paddle wheel is under the floor in the forecabin and has never worked very well. Typically it gets clogged up with weed, barnacles, etc quickly so I've given up worrying about it. Even when it works at all I found that the reading was substantially different depending on which tack I was on when the boat was heeling over.

I'm also considering fitting a wind indicator, mostly to stop myself getting a sore neck from trying to keep an eye on the top of the mast.

Mike
107 months ago (permalink)

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pjbharrison says:

I fitted a Nasa Target log and Nasa Clipper depth sounder last spring. Depth transducer fitted into recess in front of keel. Works great. Log paddle wheel fouls all the time, gave up cleaning it. I rely on gps SOG instead. Fitting paddle wheel into hull was easy with a hole saw and some Sikaflex. Left units switched on for a week and they still hadn't run down battery completely!
Bought mine on Ebay
Some available below

cgi.ebay.co.uk/NASA-CLIPPER-SPEED-AND-DISTANCE-LOG-/22068...

cgi.ebay.co.uk/NASA-Target-2-depth-sounder-boats-/2904846...
107 months ago (permalink)

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Andrew Curry says:

I have added a picture of the instrument set up on Amaryllis. I simply clip them in place to the inside of the hatch when not being used they are stored in the quarter berth. I also have a spare top washboard that has been cut out to fit round the instruments for wet/rough weather sailing. The NASA clipper works well, it’s also good to have the log/sounder in one instrument. I am using the old seafarer transducer for the sounder and it works fine so I would try yours to see if it works before changing. The log transducer is easy to fit but its not nice drilling holes in the hull. When fitting the log transducer check on what sealant they suggest you use as some plastics don’t like sikaflex (NASA are one) which I have learnt from experience when my log skin fitting cracked!! After you have fitted the skin fitting make sure you fibreglass it inside the hull which adds allot of strength to the fitting.
107 months ago (permalink)

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Super Snoopy 050 says:

Don't worry about putting holes in the bottom, we carved three great ones while putting the inboard in Snoopy. Just use lots of Isopon P40 and csm layup around the hole.
107 months ago (permalink)

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Skykomish E29 says:

Why worry about a log at all just use a GPS as most seem to these days. We used a trailing log on Aeolus, until it rained and the unit flooded and wouldn't work afterwards. I know that the GPS only gives SOG but judging by the unreliability of conventional logs this is probably more accurate, then simply deduct the tidal effect for a good estimate of Speed Through Water.

Yes Mike there is something forward of the keel on Aeolus.
We have a NASA CLIPPER unit on Skykomish and this works well but took a little getting used to after the Seafarer unit.

We bought a hand held anemometer when in Suffolk last year saves dropping the mast and running wires down it.

The next items on the shopping list are NAVTEX and AIS as these seem more important in the grand scheme of things
Originally posted 107 months ago. (permalink)
Skykomish E29 edited this topic 107 months ago.

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Red Marlin says:

Totally agree about using GPS, I am using it more and more to judge speed. I have Nasa clipper depth speed and wind. Speed log performance varies. No need for me to adjust for tide as we have none. For passage times SOG is what counts. Had to modify the old Brookes & Gatehouse housing for the clipper transducer. Tried fitting inside the hull but could not get a reading due to hull thickness. Wind is great.
107 months ago (permalink)

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rothwell_neil says:

I will stick with the GPS plotter and not drill a hole thank you.

With regard to wind instruments, I have a hand held anemometer but find that sticking your head out of the companion way and having a good look and feel tends to classify the wind into a few separate categorises that you don't find in the Beaufort scale.

Flat calm
Nice
Really nice
Boisterous and wet
Rumbustuous and really wet
Pub
107 months ago (permalink)

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jendave1 says:

Ah - the 'Beaufort Arms' scale!
107 months ago (permalink)

busy home [deleted] says:

We put a log and impeller in chille last winter,,. still not working right,
gone back to gps
107 months ago (permalink)

busy home [deleted] says:

Ive a stowe trailing log on Goskar ,, works a treat,,, Very accurate,,
Had it 20+ years They are very cheap on ebay ..
107 months ago (permalink)

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Vidwatts says:

Sensible advice here - I'm going off the idea now, however...

I do have a GPS which I use for a log - but most of my sailing is done in racing on the Thames and I'd like a clearer indication of speed to show the effect of adjustments to sail trim etc. The Thames has some strong currents, with variations across the width of the channel and it'd be useful to get a better idea of changes in speed during a race. I don't think a GPS is quite good enough for this, though I do recognise the problems with temperamental impellers.

I do have a Stowe trailing log but the narrowness of my usual sailing area doesn't really suit having a long line behind you...

If I do fit a log then I will probably fit the depth display too in a combined unit.

As for windspeed, again it would be useful in racing, especially as the Thames winds are fluky and heavily affected by the riverside buildings (the 02 can cause updrafts). I'll wait until the mast comes down (whenever that will be) and think about it then. A handheld unit may be an option if I can find somewhere to fix it and still see the display from the helm...

Thanks for your thoughts.
David
Originally posted 107 months ago. (permalink)
Vidwatts edited this topic 107 months ago.

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Red Marlin says:

Ah yes forget what I said as it applies to the Med. I have sailed a lot on the Thames (and raced a bit) you are right and for your sailing your best bet would be the NASA depth/log and wind
107 months ago (permalink)

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NormanKlipspringer is a group administrator NormanKlipspringer says:

My paddle wheel on Archimedes is forever getting fouled with barnacles and/or weed. I now keep it in the cabin with a blank in its place and only use it on a long run where I need log speed. The GPS/chartplotter SOG is accurate and if you have an estimate of the tidal vector you can get back to log speed. The best way I have found if you want to tune your boat is to use the VMG (velocity made good) information on your GPS or chartplotter. If you are using your GPS to navigate to a waypoint (GO TO) or following a route then the VMG gives you the velocity component towards your destination. This is what you want to maximise for best performance.
I find a fishfinder is much better than a sounder. Not only does it give the depth but a feel for the bottom type (sand/rocks etc). Mine which is a Garmin 90 also gives battery voltage and allows an alarm to be set for this. There are pictures of this in my photostream and previous discussions have been made. Have a look at the Flickr index on the main Achilles web site.
107 months ago (permalink)

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rothwell_neil says:

Fishfinder 90 works well for me with the transducer inside the skin of the boat and fixed looking vertically down with lots of epoxy. Signal goes straight through hull but you need to make sure that there are no bubbles in the epoxy. Originally this was fitted with silicon and that worked well for 2 years. Battery voltage a nice extra but need to remember that voltage shows state of charge only when first switched on with as little as possible switched on as this is supposed to be no load voltage.
107 months ago (permalink)

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NormanKlipspringer is a group administrator NormanKlipspringer says:

Yes I fiited my fishfinder inside hull with Slicaflex and it works with no probs. Use plenty of Silcaflex and ensure no air pockets.
107 months ago (permalink)

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rothwell_neil says:

I would like to have wind instruments and have looked at Nasa at £165 for wired and the Tacktick at £450 just to avoid pulling a cable.
107 months ago (permalink)

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