Forums > Windsurfing   Gps and Speed talk

Garmin 920XT Windsurfing activity

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Created by Nathan666 > 9 months ago, 22 Feb 2015
decrepit
WA, 12137 posts
4 Mar 2016 11:52AM
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fin151 said..
About the 2 missing runs on the fr920xt:

It might be that I paused the track and forgot to start it again. This sometimes happens to me, because I usually pause the track before a break to keep the average speed a bit higher. As you can see in the screenshot there was a break in both tracks, but then I forgot to start it again. The fr920xt continues right after 2 legs, when I noticed that it was not recording.

I wear the fr920xt on might left wrist and the canmore and gt-31 are in a waterproof bag around my neck, about 10cm below my cheek. I can do some more tracks with the canmore and gt-31 also in my left arm.

My front hand does not grab the boom from below, so the watch was always pointing upwards.


Thanks Fin151, that makes sense, it was stretching the imagination to think it took 18minutes to re-establish a fix.
It would be great to have some files with the GT31 on your upper arm. If we're using the GT31 as a reference then it should be as accurate as possible.

Good to know you don't use an underhand grip, we still need to test for this effect, to see if it's actually there or just a theory.

fin151
47 posts
4 Mar 2016 2:55PM
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There is still some ice here so I will go out the next time there is a enough wind. I can tape the GT-31 and Canmore on top of my helmet. I was 2 days ago on ice, but I had the GT-31 and canmore in the jackets pocket so I doubt they will be good enough to send in.

decrepit
WA, 12137 posts
4 Mar 2016 6:35PM
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On top of helmet would be great thanks.

fin151
47 posts
4 Mar 2016 7:49PM
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I had no tape with me, so they were in the chest pocket with the antenna to the front. These would be the results. I can email the files if those interest.

gt/31 canmore fr920xt

31.218 31.257 31.286
31.121 31.061 30.160
30.207 30.285 30.200
30.013 29.974 29.999
29.644 29.933 29.890

30.441 30.502 30.507

decrepit
WA, 12137 posts
7 Mar 2016 4:52PM
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I've done a bit more processing, here's the 2sec differences for the 920xt and the Canmore, on 22/10/15

fr920xt 2sec differences to GT31
0.019
0.059
-0.2
0.763
0.202
-0.028
0.403
-0.473
-0.628
0.008
-0.31
0.176
-0.26
-0.302
0.046
0.081
0.141
0.032
-0.199
0.319
-0.105
0.281
0.137
0.298
-0.021


Canmore 2sec differences to GT31
0.195
0.077
-0.166
-0.099
0.165
0.418
-0.138
0.455
0.193
0.252
0.175
0.437
0.347
-0.379
-0.022
0.155
0.125
-0.04
0.085
-0.001
0.098
0.165
0.107
0.205

And here's the 10sec differences
fr920xt 10s differences to GT31
-0.008
0.148
0.307
0.228
0.355
0.257
-0.114
-0.217
-0.076
0.075
0.414
-0.075
0.123
0.096
-0.186
0.053
0.05
-0.274
0.216
-0.009
-0.069
-0.381
-0.141
-0.097

Canmore 10s differences to GT31
-0.032
0.098
0.015
-0.183
0.11
-0.265
-0.071
0.036
0.129
0.097
-0.062
0.299
0.197
0.067
0.16
This one is missing due to a 1sec gap in data.
0.146
-0.042
0.166
0.142
-0.044
0.373
0.196
0.053
0.389

The 10s has less difference than the 2sec results, which is as expected. I've emboldened anything over 0.3knots, no particular reason, just seemed like a good way to compare the two. But I notice that the canmore 10s does have a 0.299 and 920 2s has a 0.298 that I haven't picked out.

N1GEL
NSW, 861 posts
17 Mar 2016 9:02AM
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Hey Fin. Pausing shouldn't make any difference to the average speed for a whole session. It will only make a difference to the moving session average speed, which KA72 doesn't look at. I always figured if you pause the device KA72 will simply see it as a period of zero speed recorded because there's no data. However, the time of the file from start to finish is still the same length whether you pause it or not.

GrumpySmurf
WA, 230 posts
16 May 2016 9:24AM
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Is there any update on this? I am sorely tempted to buy a new toy and a new Garmin smartwatch is on the shortlist. A few questions if I may:

1. Is there an updated list of compatible device? Specifically, are the "HR" models compatible as I'm looking at either the Fenix 3 HR or the Vivoactive HR, or maybe the new 735XT

2. Are these models waterproof enough to wear on the wrist without the Pacqua?

3. I have less than zero chance of breaking any records, and would be a long time yet before I get a Jelly Bean. Are these acceptable to post on GPSTC? Just a simple yes or no please - no need to go into paragraphs on Droppler etc

sailquik
VIC, 6094 posts
16 May 2016 12:13PM
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1. No.
2. Yes
3. No. But go ahead and use it for on the water feedback. It may be fine for that. You will need to carry an approved device for posting though.

decrepit
WA, 12137 posts
16 May 2016 1:29PM
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We've been asking for more data, but haven't received any, and the analysis I have done above got redthumbed. So as far as I'm concerned, I've given up on the project.

snides8
WA, 1730 posts
16 May 2016 2:37PM
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sailquik said..
1. No.
2. Yes
3. No. But go ahead and use it for on the water feedback. It may be fine for that. You will need to carry an approved device for posting though.



Yep spot on..

I have the garmin quatix 3- which is pretty much the fenix 3 but yachting version..
I have trialled it against my GT31 (aprox 6 times) and it is extremely close in producing the same numbers as the GT31.
Its fully water proof and much easier to see than the GT31/aquapack set up.
You can down load specific apps for it as well.

I run the following data fields which scroll the information while sailing

Wind/kite surfing data field
Best windsurfing run (knots)

As long as you don't fall in and have a clear view of the sky I would have great confidence in the results..
if you occasionally fall in or loose signal then verifying data may be a problem.

Even though I recon its accuracy is very close to the GT 31 (alphas included) I still think at this stage
it is best as a on water indicator only and not for posting- similar to the andoid phone/logit setup.





N1GEL
NSW, 861 posts
16 May 2016 6:31PM
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decrepit said..
We've been asking for more data, but haven't received any, and the analysis I have done above got redthumbed. So as far as I'm concerned, I've given up on the project.


No reds from me and I appreciate the time and effort you have put into analyzing the files I've sent in. Cheers mate.

fin151
47 posts
16 May 2016 6:07PM
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The vivoactive hr is not suggested because it does not support 1-sec recording. The next time I get out I take the fr920xt, gt31 and canmore with me and send in more files. I'm sorry for that. I wasn't aware of that you need more data.

At least the fr920xt and fenix3 are waterproof enough. I just have them in my wrist.

Stretchy
WA, 943 posts
16 May 2016 6:18PM
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Select to expand quote
snides8 said..

sailquik said..
1. No.
2. Yes
3. No. But go ahead and use it for on the water feedback. It may be fine for that. You will need to carry an approved device for posting though.




Yep spot on..

I have the garmin quatix 3- which is pretty much the fenix 3 but yachting version..
I have trialled it against my GT31 (aprox 6 times) and it is extremely close in producing the same numbers as the GT31.
Its fully water proof and much easier to see than the GT31/aquapack set up.
You can down load specific apps for it as well.

I run the following data fields which scroll the information while sailing

Wind/kite surfing data field
Best windsurfing run (knots)

As long as you don't fall in and have a clear view of the sky I would have great confidence in the results..
if you occasionally fall in or loose signal then verifying data may be a problem.

Even though I recon its accuracy is very close to the GT 31 (alphas included) I still think at this stage
it is best as a on water indicator only and not for posting- similar to the andoid phone/logit setup.







+1
that is exactly what I do. My FR920XT is great for on the water feedback as well as biking and running, but I don't use it for posting on GPSTC, nor am I pushing for it to be accepted for that purpose. That discussion has been done to death and is WAAAY too emotive.
Thanks Mike for doing some data comparison, I think 99% of us really appreciate your efforts

decrepit
WA, 12137 posts
17 May 2016 5:15PM
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Thanks Nigel and Stretch! But I still find myself unenthusiastic about watches.

Select to expand quote
fin151 said..
>>>> The next time I get out I take the fr920xt, gt31 and canmore with me and send in more files. I'm sorry for that. I wasn't aware of that you need more data.

>>>>


Unfortunately the files we have don't include a corresponding GT31 file with good enough accuracy to have an adequate check of the watch. Ideally the GT31 should be worn on the head. We need an sdop of around 0.2 to 0.3, most of the files we have are around 0.5 to 0.6.
If I receive any files, I'll just send them on to sailquick, he may have some time to look at them.

Stretchy
WA, 943 posts
17 May 2016 6:49PM
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I feel the same about phones, but happy others like them
great to have choices I reckon

fin151
47 posts
19 May 2016 3:39PM
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The new Vivoactive HR obviously supports 1-sec recording as opposed to the normal vivoactive. So I thought I could release the app version also (not the already release datafield version). It looks like that on the vivoactive and works on all Connect IQ devices that have a rectangular screen:



As a bonus there is a start watch included that can countdown from 4, 5 or 3 minutes.

jamesf
NSW, 992 posts
19 May 2016 10:31PM
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While the Fenix and 920 are expensive, the vivoactive HR is $399 in Aus. Still not cheap but getting better! Thanks for letting us know FIN.

www.jbhifi.com.au/collections/health-fitness-wearables

AUS4
NSW, 1255 posts
20 May 2016 8:25PM
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jamesf said..
While the Fenix and 920 are expensive, the vivoactive HR is $399 in Aus. Still not cheap but getting better! Thanks for letting us know FIN.

www.jbhifi.com.au/collections/health-fitness-wearables


Got my 920XT with Heart Rate Monitor for $450.

seanhogan
QLD, 3424 posts
21 May 2016 7:37AM
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@ aus 4, is the hear rate monitor in the watch or a separate device (chest strap) ?

cheers

AUS4
NSW, 1255 posts
21 May 2016 10:34PM
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Select to expand quote
seanhogan said..
@ aus 4, is the hear rate monitor in the watch or a separate device (chest strap) ?

cheers


Strap

GrumpySmurf
WA, 230 posts
24 May 2016 10:49AM
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Had a first short session with both the GT31 and a Fenix 3 HR. First impression on usability is excellent. Really helpful to see whats going on in the water.

As far as accuracy goes, I realise this is nowhere near as technical as you guys like it, but with the GT31 in a Pacqua on my vest shoulder, and the F3HR on my left wrist and underhand grip about 20% of the time:

GT31:
Measure?Result
2 Second Peak (kts):?22.17
5x10 Average (kts):?19.351
Top 5 5x10 speeds: (1)?20.611
Top 5 5x10 speeds: (2)?19.386
Top 5 5x10 speeds: (3)?19.135
Top 5 5x10 speeds: (4)?18.871
Top 5 5x10 speeds: (5)?18.752
Alpha 500 (kts):?12.214
Nautical Mile (kts):?11.14
100m peak (kts):?20.599
Total Distance (km):?8.666

F3HR:
Measure?Result
2 Second Peak (kts):?22.59
5x10 Average (kts):?19.38
Top 5 5x10 speeds: (1)?20.719
Top 5 5x10 speeds: (2)?19.447
Top 5 5x10 speeds: (3)?19.083
Top 5 5x10 speeds: (4)?18.887
Top 5 5x10 speeds: (5)?18.765
Alpha 500 (kts):?12.208
Nautical Mile (kts):?11.124
100m peak (kts):?20.624
Total Distance (km):?8.65

sailquik
VIC, 6094 posts
24 May 2016 2:27PM
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Select to expand quote
GrumpySmurf said..
Had a first short session with both the GT31 and a Fenix 3 HR. First impression on usability is excellent. Really helpful to see whats going on in the water.

As far as accuracy goes, I realise this is nowhere near as technical as you guys like it, but with the GT31 in a Pacqua on my vest shoulder, and the F3HR on my left wrist and underhand grip about 20% of the time:

GT31:
Measure?Result
2 Second Peak (kts):?22.17
5x10 Average (kts):?19.351
Top 5 5x10 speeds: (1)?20.611
Top 5 5x10 speeds: (2)?19.386
Top 5 5x10 speeds: (3)?19.135
Top 5 5x10 speeds: (4)?18.871
Top 5 5x10 speeds: (5)?18.752
Alpha 500 (kts):?12.214
Nautical Mile (kts):?11.14
100m peak (kts):?20.599
Total Distance (km):?8.666

F3HR:
Measure?Result
2 Second Peak (kts):?22.59
5x10 Average (kts):?19.38
Top 5 5x10 speeds: (1)?20.719
Top 5 5x10 speeds: (2)?19.447
Top 5 5x10 speeds: (3)?19.083
Top 5 5x10 speeds: (4)?18.887
Top 5 5x10 speeds: (5)?18.765
Alpha 500 (kts):?12.208
Nautical Mile (kts):?11.124
100m peak (kts):?20.624
Total Distance (km):?8.65

For this to of use to us, we need the files from the Units.

decrepit
WA, 12137 posts
24 May 2016 4:46PM
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Yep, we need to know the accuracy of the GT31 results to know how meaningful the data is.
We also need to compare the same runs, although those numbers look close, they may not be from the same run. I've see similar looking results where only 70% of the numbers correspond to the same run. It makes the results look a lot closer than they actually are.
And there's probably a few other things Daffy wants to look at.

GrumpySmurf
WA, 230 posts
24 May 2016 6:55PM
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Thanks guys. I had PM Sailquik, but for anyone that is technical and wants to view my SLOW sailing, please go to the below link. For the time being, I will upload both the GT31's .SBN as well as the Garmin Fenix 3's .FIT onto this folder.

Do note that I am a novice that is SLOW and cannot gybe :). And usually I will be wearing the GT31 on my left shoulder on my vest, and the Garmin on my left wrist. I sail with 20% of the time underhand.

www.dropbox.com/sh/gjx4fwuab8tca5j/AAALQgnLGznjahBXduTMiqQQa?dl=0

decrepit
WA, 12137 posts
24 May 2016 7:12PM
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Thanks Grumpy that's what's needed.

philn
811 posts
4 Jul 2016 5:21AM
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Select to expand quote
fin151 said..
The new Vivoactive HR obviously supports 1-sec recording as opposed to the normal vivoactive. So I thought I could release the app version also (not the already release datafield version). It looks like that on the vivoactive and works on all Connect IQ devices that have a rectangular screen:



As a bonus there is a start watch included that can countdown from 4, 5 or 3 minutes.


Do you have a link for the Vivoactive HR version? The Garmin Connect app store is not very user friendly.

GrumpySmurf
WA, 230 posts
14 Jul 2016 5:44PM
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Another slow winter session.

GT31 on Left Shoulder Strap
2 Second Peak (kts):?23.657
5x10 Average (kts):?21.696
Top 5 5x10 speeds: (1)?23.425
Top 5 5x10 speeds: (2)?22.411
Top 5 5x10 speeds: (3)?21.503
Top 5 5x10 speeds: (4)?20.842
Top 5 5x10 speeds: (5)?20.298
1 Hr (kts):?6.995
Alpha 500 (kts):?14.079
Nautical Mile (kts):?13.435
100m peak (kts):?23.417
Total Distance (km):?13.04


Fenix 3 HR on Left Wrist
2 Second Peak (kts):?23.633
5x10 Average (kts):?21.681
Top 5 5x10 speeds: (1)?23.421
Top 5 5x10 speeds: (2)?22.45
Top 5 5x10 speeds: (3)?21.389
Top 5 5x10 speeds: (4)?20.814
Top 5 5x10 speeds: (5)?20.332
1 Hr (kts):?6.988
Alpha 500 (kts):?14.102
Nautical Mile (kts):?13.346
100m peak (kts):?23.41
Total Distance (km):?12.936

Please remember to check this for actual files:
www.dropbox.com/sh/gjx4fwuab8tca5j/AAALQgnLGznjahBXduTMiqQQa?dl=0

decrepit
WA, 12137 posts
14 Jul 2016 6:45PM
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These numbers would mean a bit more if you also post their times. I've noticed when comparing these sorts of numbers, that they aren't always the same run. Which can make the 2 units look closer than they actually are.

GrumpySmurf
WA, 230 posts
14 Jul 2016 9:40PM
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decrepit said..
These numbers would mean a bit more if you also post their times. I've noticed when comparing these sorts of numbers, that they aren't always the same run. Which can make the 2 units look closer than they actually are.


I don't understand what you mean by their times. I have provided both the GT31 file and the Garmin file in the dropbox link which are "raw" data and not processed by any software or website.

sick_em_rex
NSW, 1600 posts
15 Jul 2016 11:00AM
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Decrep aren't Grumpy's numbers from a session as opposed to a 'run'? I doubt he is posting figures from a single run. How can a set of numbers from 2 units used for the same session of sailing and length of time be extrapolated differently?



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"Garmin 920XT Windsurfing activity" started by Nathan666