Weymouth Speed Week 2010 - Timing and Results Generation

In very simple terms this is achieved by each competitor recording their position accurately with a GPS unit every second of the day.

This data is downloaded from each competitor and combined into one big file at the end of the day. In addition the file created by you when you registered is available as reference data and a file of wind speed and wind direction recorded every second of each is available.

We carefully enter the start and finish time and the start and finish line information for each session and each course into Manfred Fuchs’ GPSResults software. This then calculates the time, speed, duration and direction of each 500m run recorded by a particular GT31 unit.

These “preliminary results” files for a specific day are then read by Tim Daish’s Excel macro SSerpant where some more clever calculations are performed to bring in the appropriate competitor information from the registration file, look up the wind speed and direction recorded during the run and calculate the average values and then use this data to sort and output the various results reports we require. Including speed to wind speed ratios and course angle sailed relative to the wind.

We use a Kestrel 4500 BT supplied by GPS-Speed.co.uk to log the wind speed and wind direction to a PC every second. Richard Paul  Russell imports the Kestrel units to the UK and supplies other electronics.

Note on the two types of course we operate:

1)    Harbour course
This type of course is used when the wind direction is other than south westerly. At the start end of the course there will be a lead-in buoy 150m before the start line denoting the “one competitor at a time” area. The start line is defined by an anchored boat that will be displaying the course flags. Close behind this boat (20m) a buoy will be positioned. To enter the course it is necessary to sail between the boat and the buoy. The end of the course is defined as an arc from the centre of the start line (this is done accurately by software when calculating the results). An arc of buoys is positioned to indicate to competitors 500m distance, it’s in your interest to sail fast well beyond these buoys to ensure the best possible run speed. Competitors should continue 150m beyond the course where they should then tack and make their way upwind of and well away from the course ready to make another run.

This type of course has two advantages – it can accommodate wind shifts of 20 degrees or so without needing to be re-laid and different types of craft can sail on their individual fastest wind angle.

2)    Shore course
This course is used in south westerly winds. The shore course is defined by parallel start and finish lines 500m apart. These lines extend across the harbour thereby allowing keel boats to operate in deep water whilst kites can use the shoreline shallows. The buoys will be set such that kite boards, sailboards and planing boats when on the speed course should sail on a line that is between the shore and the buoys. Sailboards should remain aware of the water depth. Those boats that require considerable water depth or have yet to test their controllability should sail well outside of the buoys thus leaving a ‘safe channel’ just outside of the buoys for other competitors to return to the course start.

This is an example of a "Harbour Course"; this would usually be used when the wind direction isn't south westerly and we have to operate from boats in the harbour.

In more detail the 'hot' area begins with a 20m wide gate (center marked by the blue symbol that can be dragged around with the mouse and placed where you set the start line. The red marker determines the center line of the 20m rectangular track). Then there are to the left and to the right of the rectangular 20m wide track two segments with half the angle you specified and a radius equal to the tracklength: