46 replies to this topic

[Pukka]

Anybody had any real time experiences with above?
Apart from some R/F interference on the Maretron (google) and a decided unenthusiastic speil from the rep at ENL
on the PB-200, I am none the wiser.(Like, we don't stock it,go figure why.)
Seeing as they have been around awhile, it is curious.

I can't rationalise shelling 1500+ clams for a B&G & they don't output NMEA anyway,do they?

[New Morning]

Search Panbo.com Dan Corcoran did an extensive review on the second generation (aka 200) and loves it.

[Moonduster]

Tried to send you a PM but got some error saying "The member cannot use the messaging system" - perhaps you're not quite setup right?

PM me with some contact info ...

Basically, ultra sonic sensors have huge potential but don't seem very well developed for sailing. There's a reason that none of the high-end programs (AC, TP52, Volvo, etc) use ultrasonics - even at the expense of heavy and draggy 1.5 meter mast head wands.

Is your interest only lower cost? Are you aware that most NMEA interfaced systems are too slow to provide meaningful true wind data? What kind of instrumentation system are you trying to get this wind data into?

[Slowboat]

Moonduster - the PB200 does true wind direction and speed calculations in the transducer it's self. In addition to the ultrasonic wind sensor, it has a pretty sensitive WAAS GPS and 3-axis solid state compass. As I said, all the processing happens in the unit, so it can output the info over NMEA 0183 just fine. It also outputs via NMEA 2000, if you can use the data - perhaps into a computer, etc.

I would like to hear your thoughts on the downside of ultrasonic senors - I know that they can be screwed up by rain, fog and snow - are there other downsides?

You can read the Airmar info at:
http://www.airmartec....asp?ProdID=105

The PB200 WeatherStation instrument informs you of instantaneous changes in the weather around you. Wind Speed and Direction are measured using four ultrasonic transducers. No moving parts results in better durability and reliability. The internal WAAS GPS engine and three-axis, solid-state compass make it possible for the PB200 to provide both Apparent and True Wind Speed and Direction without the need to add on additional sensors. Additionally, the WAAS GPS provides navigation data as well as magnetic variation and is suitable as your primary GPS source. The internal temperature and barometric pressure sensors help predict changing weather patterns. Combined with the internal heading sensor, all of your navigation needs are provided! No other sensor on the market incorporates all of these sensors in one compact housing. What sets us apart from the PB100 and the competition is the ability to provide 2° heading accuracy under dynamic conditions, such as rough seas. Airmar's unique dynamic motion correction software is the key difference. The PB200's heading is highly accurate and stable under most sea conditions, even if the vessel is pitching and rolling up to 30° in rough seas. Also unique to the PB200 is that the 3D accelerometer and rate gyro are temperature compensated resulting in precise tilt and rate of turn data. This allows the PB200 to accurately measure True Wind Speed and Direction even when tilted up to 30°.

[Pukka]

Search Panbo.com Dan Corcoran did an extensive review on the second generation (aka 200) and loves it.

Thanks for that. Comments after that article are interesting.

Moonduster-PM'd you. Presume it got there. (I did not have pm'g enabled.)

[DDW]

I bought a Maretron and never mounted it. One thing about a traditional wand, it gets it out in front of the usual antenna farm at the truck. These ultrasonics mount on a 1" pole, makes it a little hard to deal with. It would be nice if they would come up with one packaged for sailboats, not powerboats. Another issue is you have to run the Canbus cable up to the masthead.

I could probably be talked out of the Maretron at a substantial discount if you were interested. Seems to me that the Airmar is more sophisticated though.

[Sailing Harry]

Ok, I know this thread is over 2 years old. But my question is nearly identical, so why start a new one.

The PB200 sounds terrific. Some say it isn't up to Grand Prix performance -- but not much at this price range is!

What I see as "plus"
* Includes magnetic compass -- so outputs ground wind at anchor
* Outputs NMEA 0183 wind --works with my old autopilot
* Outputs NMEA 2000 -- works with new instruments
* Can't be broken by birds
* Includes GPS (who can't use a spare -- perhaps dedicated to DSC VHF?)

What I see as "minus"
* At this price and benefits, how come they aren't pushing 5-10% market share? Why are few folks talking about them?
* How best to mount at masthead?
* Is the magnetic compass nearly worthless in a seaway? I only sail the Chesapeake, not the Southern Ocean.
* How come no one "bundles" it? I'm looking at a GMI10 system -- the included wind unit is $500, the PB200 is $1200 -- but a-la-carte the GMI10 is VERY expensive!

Any updated thoughts on the ultrasonic systems? Panbo seems to have about 95% of the total internet discussion on this item!

[mike_new]

Ok, I know this thread is over 2 years old. But my question is nearly identical, so why start a new one.

The PB200 sounds terrific. Some say it isn't up to Grand Prix performance -- but not much at this price range is!

What I see as "plus"
* Includes magnetic compass -- so outputs ground wind at anchor
* Outputs NMEA 0183 wind --works with my old autopilot
* Outputs NMEA 2000 -- works with new instruments
* Can't be broken by birds
* Includes GPS (who can't use a spare -- perhaps dedicated to DSC VHF?)

What I see as "minus"
* At this price and benefits, how come they aren't pushing 5-10% market share? Why are few folks talking about them?
* How best to mount at masthead?
* Is the magnetic compass nearly worthless in a seaway? I only sail the Chesapeake, not the Southern Ocean.
* How come no one "bundles" it? I'm looking at a GMI10 system -- the included wind unit is $500, the PB200 is $1200 -- but a-la-carte the GMI10 is VERY expensive!

Any updated thoughts on the ultrasonic systems? Panbo seems to have about 95% of the total internet discussion on this item!

One of the PROs told me last week that they are no good, at least for Racing.
Here is another one:
www.lcjcapteurs.com/ (web refurbishement in progress)

[savoir]

To admit that ultra sonic sensors are good for racing is to put a hell of a lot of products into the trash can.

If you get one, don't put it on the masthead - they are too sensitive for up there.

[VALIS]

To admit that ultra sonic sensors are good for racing is to put a hell of a lot of products into the trash can.

If you get one, don't put it on the masthead - they are too sensitive for up there.

"too sensitive up there"? Please explain. If you mean that they respond instantly to masthead motion induced wind, then isn't that a good thing as long as the speed / direction vector is accurate? Does the inertial damping of the mechanical-style windex somehow improve the resulting data?

[henry the navigator]

SDD and peer pressure is the reason you don't see them. SDD = Sailor Decision Disorder.

Tested above to a B/G static detector about 100' up for a season. No problems.

[Barley]

Ok, I have been using a ultra sonic detector for the past 3 years. It is the Airmar PB 250. It is connected to an Ockam system via a custom Ockam interface. Mast height is 75 feet.

1st: You need a really sturdy mount. The detector weighs a ton compared to the old 36 inch bent wand. The inertia is impressive. I think my current mount is about 20 inches high. When you hold it/swing it around the amount of force that weight exerts on the bottom end is alot more than I expected. Now add another 75 feet to that. Going upwind in moderate waves must create huge forces. Because of this, I am thinking about having the wand shortened to about 10 inches.

2nd: I have been told, no personal experience, that the compass is useless up there. The amount of motion is just too much. Look at the top of you mast in small waves and see how much it moves around compared to the deck and you quickly get an idea how hard it would be for a compass to give quality readings. Same for the gps.

3rd: It also gives temp and barometric pressure. Sure not the most useful info on a racing boat but its available. We use the barometric pressure reading and its trends just to track the weather.

4th: They are really accurate and really sensitive. But you have to put some effort into setting up the averaging to get quality data for the instruments to use. If the averaging is too slow the delay will drive you insane. You feel the lift and 20 seconds later the instruments show it. Too fast and you get crazy data, for example in light wind conditions with waves causing the mast to move back and forth you get useless data. Still not totally happy but working on finding a happy medium. Now I know this is true with any system but I will tell you its more pronounced with the ultrasonic detectors. Their data has no delays. With the traditional wind indicator you have to overcome inertia, etc. However it is really cool on a still morning to watch the wind speed indicator pick up speeds of .2 to .9 knots and the wind direction indicator is showing the direction, while you look over at all the surronding boats (including those with higher masts) and there tradition wind detectors are not moving

So why are they not popular. Well I think the weight is a real issue. I am still considering going back to a traditional bent wand not just because of the classic "limit weight up-top issues" which is very important, but because of the tremendous forces it is applying to the mast mount. Not sure I want to be on a long upwind slog to Bermuda and hope the mount lasts. Also the standard bent mount is way cooler looking than the strait mount for the ultrasonic detector. Not really that important but just saying. Also do many current instrument systems have a "cheap" way to intergrate a ultasonic detector. Mine was very expensive (I know its Ockam), but what about everyone else, B&G, NKE, Raymarine, Nexus, etc. I didn't realize those compaines had interfaces.

In a perfect world ultrasonics should rule. If the weight was less. Cost was less. Easy intergration into curent systems. Then maybe you would see more of them

[Presuming Ed]

Accuracy of the Airmar doesn't look great when it's raining? From the specs:

Wind Speed Accuracy @ 0°C to 55°C (32°F to 131°F), no precipitation*:
— Low Wind Speeds: 0 knots to 10 knots (0 MPH to 11.5 MPH); RMS error of 1 knot (1.1 MPH) +10% of reading
— High Wind Speeds: 10 knots to 80 knots (11.5 MPH to 92 MPH); RMS error of 2 knots (2.3 MPH) or 5% RMS, whichever is greater
Wind Speed Accuracy in wet conditions**: 5 knots (5.7 MPH) RMS

[Resentful Dawg]

Tried to send you a PM but got some error saying "The member cannot use the messaging system" - perhaps you're not quite setup right?

PM me with some contact info ...

Basically, ultra sonic sensors have huge potential but don't seem very well developed for sailing. There's a reason that none of the high-end programs (AC, TP52, Volvo, etc) use ultrasonics - even at the expense of heavy and draggy 1.5 meter mast head wands.

Is your interest only lower cost? Are you aware that most NMEA interfaced systems are too slow to provide meaningful true wind data? What kind of instrumentation system are you trying to get this wind data into?

I know of 2 programs using the ultrasonic sensors in the AC, Team NZ and Artemis. TNZ even put out a video while calibrating the wands with the ultrasonic as reference.....

[Moonduster]

You've missed the boat. They're calibrating the wands because they're not using the ultrasonic on the boat. It's a fine reference in a test setup, but not so much use on a yacht.

[henry the navigator]

Moonduster,

Are you suggesting the ultrasonic sensor is being used to calibrate the analog wind sensor?

Is the ultrasonic sensor too heavy to use while sailing?

Have you seen many problems using the ultrasonic sensor?

What is the wind sensor of choice now?

[diggler]

Anyone know of any work that has been done on characterizing the off axis response of these ultrasonic units? Horizontal axis turbines like the Nexus have a nice cosine response, vertical axis cup anemometers do some odd things but assuming something close to constant over normal heel angles usually seems to work out ok. But these? I imagine the vendor specific design of the measurement gap would have a big impact, and it won't be anything linear - next to zero at small heel angles and dropping off very quickly above some threshold where the gap stalls out.

[mowgli]

I was thinking about to instal one in the center on the back off the boat on a small pole. How accurate are the readings then also with a normal transducer?
On my new boat I have a rotating mast so I don't need a mast rotation compensatort and for trailering you don't have to dismantle it from the mast. Any thought about this setup.

[nyker]

When sailing close hauled the sensor will be in the ' downdraft' of the sail and the reading will be inaccurate. I will have the same problem for my F85SR. I allready thought about using 2 sensors on poles on the aft beam ends and using a heal switch to select the upwind sensor. I understand that the airflow, only a few meters above the water will be too turbulent for autopilot use. But it might be ok for instruments.

[diggler]

This makes no sense. For the cost of two sensors and a heel switch you can get a mast rotation compensator and put one sensor on the mast and actually get useful data.

[savoir]

When sailing close hauled the sensor will be in the ' downdraft' of the sail and the reading will be inaccurate. I will have the same problem for my F85SR. I allready thought about using 2 sensors on poles on the aft beam ends and using a heal switch to select the upwind sensor. I understand that the airflow, only a few meters above the water will be too turbulent for autopilot use. But it might be ok for instruments.

" too turbulent for autopilot use " ? Who says that ?

[mowgli]

This makes no sense. For the cost of two sensors and a heel switch you can get a mast rotation compensator and put one sensor on the mast and actually get useful data.

Is there a mast rotation compensator that will work with a PM200?
Airmar don't have one so far I know.

[diggler]

Is there a mast rotation compensator that will work with a PM200?
Airmar don't have one so far I know.

No, not that I am aware of. For that you'd need to roll your own. Not terribly difficult to do if you go with the 0183 version and an Arduino, but you do have to have the inclination. Or really long, cold, dark winters...

I remember reading about some guys over on one of the Yahoo F-boat groups that liked the results they got from putting a PB200 on the bow sprit. Since the apparent is rarely aft of the beam on those boats I guess it is probably about the best option after the mast head, as long as you aren't sailing in really rough stuff and dunking the unit a lot.

My comment to Nyker was implying dropping the ultrasonic sensor and going with one of the few instrumentation systems around that accomodates rotating masts, like Nexus. Maybe lacking motion compensation for the wind sensor, but overall a much more useful instrumentation system.

[mowgli]

Is there a mast rotation compensator that will work with a PM200?
Airmar don't have one so far I know.

No, not that I am aware of. For that you'd need to roll your own. Not terribly difficult to do if you go with the 0183 version and an Arduino, but you do have to have the inclination. Or really long, cold, dark winters...

I remember reading about some guys over on one of the Yahoo F-boat groups that liked the results they got from putting a PB200 on the bow sprit. Since the apparent is rarely aft of the beam on those boats I guess it is probably about the best option after the mast head, as long as you aren't sailing in really rough stuff and dunking the unit a lot.

My comment to Nyker was implying dropping the ultrasonic sensor and going with one of the few instrumentation systems around that accomodates rotating masts, like Nexus. Maybe lacking motion compensation for the wind sensor, but overall a much more useful instrumentation system.

Diggler tanks for the comment, I am going in november to the Mets and going to visit the Airmar stand maybe I can talk the in to develop a software option for it to work with a other digital compass on the boat to calculate the rotation of the mast. (the pb200 has its one compass build in)

[Moonduster]

Couple of comments:

Henry,

I'm not suggesting it - that's what the video implies. Take a look for yourself.

Mowgli,

Deck level sensors aren't ideal. Neither is having the sensor so far aft will cause weird effects due to apparent wind that is induced as the boat's stern slews around, especially when surfing off down wind - this can cause significant oscillation problems when feeding wind direction data to an auto pilot. Also be careful about the amount of spray that might wind up directed into the sensor when sailing up wind - take a look at the derating for accuracy in the rain and then multiply that a few times for the effects of sheet spray.

Regarding mast rotation -

NKE, B&G and Nexus all support mast rotation sensors. Either Nexus or NKE uses a clever dual compass approach where one compass is the normal fixed compass and the other in mounted inside or onto the mast. The differential of the two compasses is mast angle. The problem is that compasses aren't super accurate and there's no synchronization in the time domain of the two compasses so it's easy to induced 1-4 degrees of rotation error and that has a huge effect on the true wind direction math and, worse yet, it's prone to oscillation problems.

I'm not aware of any other commercial solution that has direct support for rotating masts, although I'm sure that the Cosworth system, not exactly an off-the-shelf solution, does too.

[nyker]

This makes no sense. For the cost of two sensors and a heel switch you can get a mast rotation compensator and put one sensor on the mast and actually get useful data.

Money wise you are right.There is a drawback however. Mast rotation compensators are not very accurate up till now as there are fluctuations in the compass readings which add up. On trimarans there is often a big difference between AWS and TWS, This means that a few degrees of uncertainty has a lot of influence.

" too turbulent for autopilot use " ? Who says that ?

That is what Woolfy ( nexus ) wrote when I mailed him some questions about using TWS and the possibility of using a heel switch for selecting the upwind sensor. Wind direction and speed @ 2 meters above sealevel seems to be more turbulent than at mast level.

It will be a few years before my boat is ready and I hope that there is a good solution by then. I think it would be nice to have a modified rudder angle transmitter coupled to the wind information. This rules out compass variations.

[diggler]

Money wise you are right.There is a drawback however. Mast rotation compensators are not very accurate up till now as there are fluctuations in the compass readings which add up.

What do you mean, add up? There is no integration of the angle, so the error is the error. The Nexus system really heavily dampens the mast compass value, so unless you have one of those special boats that manages to roll a few more degrees to port than starboard every oscillation, you should be fine dynamically which just leaves you with hard iron errors.

No system that I am aware of makes any effort to account for the hysteresis inherent in the response of cup anemometers which leads to increasingly overestimated wind speeds with increasing turbulence. Most systems make no allowance for leeway, and those that do tend to use a pretty rough approximation. Unless you splash out big bucks on the reasonably fast NKE ultrasonic sensor, you are measuring speed with a paddlewheel or a very slow airmar sensor. Errors in the boat speed vector are as just as significant as those in the apparent wind vector.

My point here is that I think you are worrying far too much about one source of error to the exclusion of others and the system you are contemplating will suffer even poorer performance for it.

NKE, B&G and Nexus all support mast rotation sensors. Either Nexus or NKE uses a clever dual compass approach where one compass is the normal fixed compass and the other in mounted inside or onto the mast.

This NKE mast rotation sensor
http://www.nke-marin...unt-sensor.html
is quite clearly not a compass. It is in fact exactly what Nyker was asking for. The price for a full NKE system hurts too much for me. Sure would be nice to have one of their pilots though.

[savoir]

This makes no sense. For the cost of two sensors and a heel switch you can get a mast rotation compensator and put one sensor on the mast and actually get useful data.

Money wise you are right.There is a drawback however. Mast rotation compensators are not very accurate up till now as there are fluctuations in the compass readings which add up. On trimarans there is often a big difference between AWS and TWS, This means that a few degrees of uncertainty has a lot of influence.

" too turbulent for autopilot use " ? Who says that ?

That is what Woolfy ( nexus ) wrote when I mailed him some questions about using TWS and the possibility of using a heel switch for selecting the upwind sensor. Wind direction and speed @ 2 meters above sealevel seems to be more turbulent than at mast level.

It will be a few years before my boat is ready and I hope that there is a good solution by then. I think it would be nice to have a modified rudder angle transmitter coupled to the wind information. This rules out compass variations.

Oh well, my PB 200 works just fine at 4m above sea level. My only problem is too much data. A project for next summer is using the averaging function to try and settle it down.

[mowgli]

This makes no sense. For the cost of two sensors and a heel switch you can get a mast rotation compensator and put one sensor on the mast and actually get useful data.

Money wise you are right.There is a drawback however. Mast rotation compensators are not very accurate up till now as there are fluctuations in the compass readings which add up. On trimarans there is often a big difference between AWS and TWS, This means that a few degrees of uncertainty has a lot of influence.

" too turbulent for autopilot use " ? Who says that ?

That is what Woolfy ( nexus ) wrote when I mailed him some questions about using TWS and the possibility of using a heel switch for selecting the upwind sensor. Wind direction and speed @ 2 meters above sealevel seems to be more turbulent than at mast level.

It will be a few years before my boat is ready and I hope that there is a good solution by then. I think it would be nice to have a modified rudder angle transmitter coupled to the wind information. This rules out compass variations.

Oh well, my PB 200 works just fine at 4m above sea level. My only problem is too much data. A project for next summer is using the averaging function to try and settle it down.

Where is your PB200 place on your boat?

[savoir]

It sits on an antenna pole on the port quarter.

[nyker]

What do you mean, add up?

I'm not talking about dynamic variations caused by mast movement. These will generally be filtered out. Most mast rotation compensators use a second compass on the mast to compare headings with the main compass and calculate apparent wind direction. For total system accuracy you have to add their inaccuracy values as the two compass readings are used to calculate wind direction.

I know Maretron have a solid state compass that they claim has an accuracy of 1° ( under static conditions ) but most compasses have a lower accuracy.

I've seen the NKE sensor and agree with you on the price issue

regards

Nico

[diggler]

Ahh, see what you mean by adding up. Duh.

[Aremmes]

Couldn't the PB200 compare its compass reading with the GPS heading (provided that it knew the local magnetic variation) to compensate for mast rotation? If Airmar can't include it in a firmware update, maybe they should be working on a follow-up to the 200WX.

[nyker]

No. Because then you also have to correct for drift and current.

[diggler]

It has also been pretty well established that the compass and gps data from the PB200 is fairly useless if it is flopping about at the top of a mast.

[TACNI]

I believe Ockam systems can use a mast rotation sensor like a string pot to correct for mast rotation. A much better way than using the difference in heading between the boat and the mast.

[Moonduster]

The complication with the string-pot approach is that the string usually winds around the mast as it rotates in at least one direction and, as a result, the string motion isn't linear with mast rotation. It's a manageable problem, but a bitch to construct the tables to translate between the coordinate spaces.

And string pot reliability isn't so great.

[mowgli]

I did find the following on the site of lcjcapteurs:


Option CV7-C-CanBus :

CV7-C Canbus is compatible with NMEA2000® systems featuring a wind functions page.
The CanBus option includes a barometer (suitable for systems featuring a barometer functions page).
This option is available by adding a "Black-Box" interface.
These instruments have been tested with the CV7-Canbus:
B&G© : Triton.
Furuno©: FI50, RD33, NavNet2, NavNet3.
Garmin© : GMI10 (whole range).
Raymarine©: i70.
Simrad© : whole range.
Option CV7-C-RM:

CV7-C-RM for sailboats with rotating mast.
CV7-C-RM allows connecting the CV7 mast head sensor to any NMEA2000® compatible instruments.
http://www.lcjcapteurs.com/product/cv7-c-is-the-high-speed-ultrasonic-wind-sensor/?lang=en

[patrik111]

It has also been pretty well established that the compass and gps data from the PB200 is fairly useless if it is flopping about at the top of a mast.

Reading the panbo writeup I would much like to read the "other side", where can I find that?

[Sailing Harry]

It has also been pretty well established that the compass and gps data from the PB200 is fairly useless if it is flopping about at the top of a mast.

Seems I lost track of this thread -- and it's one I'm pretty interested in. But I'm back.

Where/how has it been established, by real users (not theoreticists, but users) that the compass/GPS data is bad because it's at the mast head?

I can accept that the GPS is poor, since it takes position fixes every few instants and uses that for data. I think one user I read of took a hand held gps and waved it around his body, and got wild results. I know my handheld can get course/speed when I simply walk across my 20' patio! But if you use the GPS for nothing but a backup nav source, I'm very happy with 50' error readings!

The compass is different. There is ZERO inertia, and inertia is what makes your card-compass spin when you shake it. The compass may move violently, but it does NOT rotate, at least not much, and identically to the rotation of the boat. The flux direction through the compass is constant as the compass thrashes, and so should produce a steady result. It is true that the compass will rotate around a horizontal axis, and that coupled with the vector math will induce errors, but the PB200 has a 3-axis compass and should be able to calculate that out.

The compass is one big factor in this decision. A typical windmill sensor is $500, perhaps more. A typical NMEA 2000 compass to add to the sensor mix is at least another $500. That makes the price of the PB200 tempting -- but if the compass is of no value, then it looses its charm.

I'd love to hear actual users who actually installed the unit and found the compass to be a problem.

And while compass readings that bounce around by 1 or 2 degrees may be an issue for people that have $50K annual budgets (and those people think nothing of replacing wind units every time an Osprey sits on it!), us cruisers will be very happy with a +/- 3 degree unit if it works fine and never dies from an Osprey.

Harry

[diggler]

read about flux gate compass sensors and their sensitivity to accelerations. way bigger errors than one or two degrees.

[snikabo]

Hi

I've read trough the entire thread and non the wiser.

I'm looking for a reliable wind sensor to be used on a weather buoy.
As I understand Airmar pb-150 calculates TWD automatically, so if the buoy rotates its corrected.
There is less maintenance with an ultrasonic sensor compared to a cup/vane sensor.

One drawback is that concerns me is accuracy when it rains, how bad is it?

Is there any other wind sensor system better suited for use on weather buoys?


Snikabo

[crashdog]

i've just ordered LCJ Captuers CV-7 C from Pochon. I have no idea if it will work at all, and since I often forget to put the instruments on when I go sailing, I am not sure if I can accurately compare it to anything at all. After all, we never had no stinkin wind instruments in the Star.

However, Vancouver has frustratingly light air, and the mast tip motion caused by the crew reaching for their beer is going to introduce a substantial error into the wind calc so it will be an ideal environment to test accuracy. I will report in due time.

[diggler]

One drawback is that concerns me is accuracy when it rains, how bad is it?

I've not been able to find any good info on this either. Looking forward to hearing how crashdog does with his unit. If there was a decent chandler near me I would just buy one and test it.

I also haven't found any good info on how the response of these units changes with heel/pitch angle. I expect there is a nice operating pocket outside of which things get very non-linear very quickly. Could be an issue if your weather buoy is going to see some big waves.

[WHL]

i've just ordered LCJ Captuers CV-7 C from Pochon. I have no idea if it will work at all, and since I often forget to put the instruments on when I go sailing, I am not sure if I can accurately compare it to anything at all. After all, we never had no stinkin wind instruments in the Star.

However, Vancouver has frustratingly light air, and the mast tip motion caused by the crew reaching for their beer is going to introduce a substantial error into the wind calc so it will be an ideal environment to test accuracy. I will report in due time.

The big question is: will it get you past Raven ??

[crashdog]

Maybe if it blows. The boat is sticky in light air. Maybe the instrument will be able to tell me when its too light to bother...

[savoir]

You should mount it on an antenna pole - if you have one.