The GPS-Speed sailing community consists of thousands of mainly Windsurfers and Kite-surfers around the world who use a GPS device to log their speeds to compete in a number of competitions. There’s one crucial factor that differentiate our use of GPS in our specific sports and that’s: “verifiability”

Since around 2004 we have used a number of different consumer GPS loggers and have dramatically improved our accuracy as hardware and software has evolved through different models.We have developed a unique way to measure & validate GPS Speeds. This all results in a very high level of measurement of GPS data and a world wide competition of windsurfers & kiters, the technique that's used is based on "Doppler" .

It's a method for estimating the accuracy of GPS-Doppler speed measurement using Speed Dilution of Precision (SDOP) parameters. Direct measurements of GPS-Doppler speed errors are confronted with theoretical SDOP predictions. Comparison reveals that SDOP is a very useful and practical parameter for determining accuracy of GPS-Doppler speed measurement. It is demonstrated that 10-second average speed can be measured with accuracy better than 5 cm/s and confidence better than 99.9% using Doppler enabled GPS logger.

At this moment we have several GPS Devices officialy approved for posting Record Sessions on

All session posted with a doppler device have this green icon -> 

In the last few years the quality of standard non-doppler GPS devices have improved a lot. For that reason we have decided that we approve non-doppler devices for the so called fun-rankings and day-to-day use. Altough results of non-doppler devices are often close to doppler-recorded session there is no way we can verify the actual speeds that have been recorded. For that reason we do not allow non-doppler devices sessions in our record rankings.  

  • More information about generic GPS Devices (->
  • For speedfreaks that already own a Android phone a good alternative could be the App GPS Logit, The App produces doppler speeds, at the same quality level of the old GT-11 .The App records Dopplerspeeds from the GPS-chipsets that are implemented in all recent smartphones, so the accuracy is comparable to a GT11, the only missing item is the Dopplerspeed-error (SDOP). For record purposes it is not suited, however, for fun rankings it is way better than e.g. positional data from standard units. (-> )

All session posted with a non-doppler device have this orange icon ->