There is a lot of discussion on this forum about gps devices and their various accuracies, etc. Keep reading. You will find a lot of info here.

I never post speeds to records, but I use a Garmin 255 watch for general windfoiling. It, and its followers, is one of the recommended devices.

I use Waterspeed on my Apple Ultra watch, which I find gives pretty good results (compared to my Mini Motion). Before the Ultra I had an Apple v6 and the results from that were unreliable. I only post results to GPSTC using my Mini Motion, but for winging i only post to KA72, so I use Waterspeed and my Ultra for that (simpler). Sadly no big Waterspeed winging speeds from me though :(

I have seen the occasional spike, which usually relates to a crash and the watch being underwater. A spike is pretty obvious when you look at your track and that section can easily be trimmed out with Waterspeed, however sometimes they don't appear until you upload the gpx to KA72. If this happens, I'll remove the post from KA72, fix the track, then repost. If people just post their results blindly without checking - in KA72 - that their numbers are reasonable and their track looks right, then I can see how problems could arise. To be fair, you should check that your results are valid no matter what gps and app you use.

Garmin is having a sale now too

mikey100 said..
Have seen 'Waterspeed' listed as the gos device on some recent KA72 files of wingers lately and wondered about the accuracy of the gps unit which seem to be recording big speeds in OZ lately.

All depends on the watch, some are horrible, some are great.
Good ones within 0.5kts.
Bad ones +/- almost 2.0 kts.
And anything inbetween.

Now there's a mystery!

It seems you can export any GPX file from waterspeed. I uploaded data from the coros watch to waterspeed then exported the GPX file. When loaded to KA72 then is shows as waterspeed. No need for bike rides I'll assume if the app is on your Garmin or Apple phone it registers the device, but if you do the direct export from waterspeed it registers as waterspeed.

remery said..
It's be interesting. sunny tomorrow. Windsurfing in winter is not my thing. But I could go for a ride on the pushbike while wearing a Garmin 255, Motion and running Waterspeed on the Android phone, if thats a help.

Would be interesting

I imported a couple of FIT files into the Waterspeed app, it showed track, distance and heart rate but no speeds.

Michael George has spent some considerable time compiling details of many current model GPS units. There is mention of the the apple watches and the waterspeed app.

logiqx.github.io/gps-details/

Stretchy said.. If people just post their results blindly without checking - in KA72 - that their numbers are reasonable and their track looks right, then I can see how problems could arise. To be fair, you should check that your results are valid no matter what gps and app you use.

that's been the issue since the start of KA72
Ignorance was bliss ??
In the early days captains used to scrutinize tracks, at least in WA ??