Conditions of Entry:

In order for people to create a team they must submit a signed registration form and send this form to the email address info@ for this website.

To join an existing team, click the "Register" link in the login box.


No limit to number of members per team.
No limit to teams per state.
The competition is teams vs teams based.
To qualify for a team session, at least two team members must have sailed that day and recorded results. Individual results alone, will not be counted towards a team session.
Sessions will be defined as windsurfing sessions by team members on the same date, local time, however, the location can be different for different team members.

There will be 6 measurement categories.

  • 2 sec peak;
  • 5 x 10sec average;
  • 1 hour;
  • Alpha Racing 500m;
  • Nautical Mile.
  • Distance travelled in a day, sum of multiple sessions.

Points will be awarded in each category, and summed for an "Overall" category.

Teams that don't supply a session score/time/result for a category in any month will be awarded the maximum points.


You are responsible for your own data. You must believe that you actually did a certain speed before you post that number, however you work it out. This website works mostly by the honesty system, and if you aren't honest with your numbers, then you will be found out eventually.

Data Verification:

You must be able to produce the data file for any session that you sail. At any time you may receive a request for this file for verification. Failure to produce this file in its original format may result in the session being deleted, and, in a penalty being applied to you and/or your team.

Measurement Definitions:

The 'Average' score for each category will be the average of the top two scores for the team, recorded on that day.
This encourages everyone to post every session, as you can never disadvantage your team by posting.

Measurement Method:

Speeds recorded should be Doppler and from a GPSteamchallenge approved GPS and recognised software, primarily, KA-72 Speedlocker, GPS-Results, GPS-Speedreader, RealSpeed and GPSAR-Pro.

The GPSteamchallenge technical advisory panel has liaised with the various recognised analysis software authors on a standard set of filter values, definitions and methods for calculating results. These values are normally the default values in the software. They vary between different types of approved devices and may be further varied if the technical advisors have a consensus. Notwithstanding these default filter values, we recognise that analysis software is not infallible and the GPSteamchallenge may over rule software results based on the GPSteamchallenge teams considered analysis and their rulings are final.
A document outlining the agreed filter settings, definitions and measurement methods for analysis software will be available on request.

Special Note:

Technical Advisers for the challenge will be as follows: Roo (NAVi GPS) Sailquik (General) and Slowboat (General). The Rules advisory panel may define the rules for the purposes of this challenge. These will be updated on this page. The following GPS's are considered valid for the purposes of the challenge (most preferable in bold, least preferable and conditional at the bottom):

  • Motion*
  • GW-60 **
  • GW-52
  • NAVI GT-31 (uses 1 sec recording intervals)
  • NAVI GT-11 *** (uses 1 sec recording intervals)
  • Canmore GP-102 **** (conditional, and to be phased out by 2020) (use 1 second recording intervals)

Notes on Approved GPS devices for posting on GPS-TC:
The current policy of GPS-TC is that Motion, GT-31, GW-52 or GW-60 must be used for posting Doppler based data (D) by individuals vying for the top positions, and by team members contributing to monthly team ranking scores (commonly called "Jellybeans")

The motion GPS must only be used at 5Hz or 10Hz*
'Smart Logging' on the GW-52 and GW-60 should not be used
The GW-60 should only be set for 5hz logging**.

*** GPS-TC also allows the legacy GPS, the GT-11 which has Doppler speed data, but only for those sailors not in the category mentioned above.
Note: The previously grandfathered, Legacy GPS's, mainly Garmin Foretrex 201 and Garmin Geko, which used positional speed data (T) are removed from the approved list as of March 2019.

* Motion GPS settings and use:

  • FW V.988 and newer
  • Posting using 5Hz or 10Hz only. (1Hz or 2Hz not allowed)
  • .oao or converted .ubx or .sbp files only, and expressly not allowing posting from files converted to .gpx format.
  • Posting from approved Software analysis programs only: GPS-Results V6.161 or later, GPSAR-Pro V5.21 or later, Realspeed V2.001, KA-72 Speedlocker
  • Note: Posting from the screen results or the text digest file is specifically not allowed.

** The best mode for accuracy in the GW-60 is setting it to 5hz logging. 'Smart logging' should not be used for posting. (based on recommendation by Manfred Fuchs as a result of his testing)

***The Canmore GP-102 has been approved for use as it sits somewhere in between those already mentioned. It has the potential accuracy of the GT-11 as it is a Doppler based device, but it has very limited verifiability. If you are posting results that are counted in the team challenge in a competitive team you should inspect the results closely in a stand-alone analysis program (GPS-Results/GPSAR-Pro/RealSpeed) for unusual results and errors. Preferably, team captains or the team 'tech guru' should help with this, and if there is any doubt the files should be sent to one of the GPS-TC technical advisors for a second or third opinion. This GPS is to be phased out by 2020.

Check out discussions on Seabreeze for more information or to get help from the GPSTC community.

Other GPS units can be approved by the technical advisers of the challenge, including Ublox GPS chipset based, custom or home made devices.

Using multiple GPS's

GPS devices sometimes can fail, or users can sometimes make errors in use that can result in lost data, or no recorded data on a device, so users are encouraged to use multiple GPS's if they wish to have backup redundancy. In such cases, users should select the complete set of data from only one of the devices to post, preferably from the device with the lowest +/- numbers, unless the technical panel gives an individual case approval.

Sessions will be submitted by the individual user. Every session in a month can be submitted, and the computer data base will calculate which are the best speeds recorded for the month to count as the team score. Each team score will be rank ordered against other teams and a score awarded in each category from lowest to highest. eg. if there are 16 teams in a given category that have submitted a time these will be awarded points according to rank ordering, from a 1 for best time/speed, to 16 for worst. This is done in each category, with the team having the lowest points for the month, being the leading team for the month.


Results will be continually updated on the internet website each month. Winning team/s each month can have bragging rights for that month. Verification of results, needs to be possible, therefore each team members session results needs to be available for scrutiny. (This can be requested at any time). Ensure that a data file is kept of each session on your computer. Monthly scores are summed (added) for the number of months the competition runs.

Discards will be awarded for the 2010 competition onwards so the Australian team competition will have 1 discard per year, while the international team competition has 4 discards per year.

An overall category (and Challenge Winner) is the team that has the lowest score across all 6 categories over the year.

Duration of competition:

The competition runs annually.

Other competition periods may be announced from time to time.

All team speeds for a given month need to be recorded in the database within 7 days of the end of that month. For example, to post a session in January, you must do so before the 7th February.