Estimating accuracy is tricky, because most of the errors in the GPS position measurement vary slowly with time and so cancel out in speed calculations. Perhaps the best measure is the velocity indicated at rest, which is usually less than 2kph. Positions are measured once per second, and the maximum speed indicated is the average over this time, which means that lurching forward could give a misleading velocity for that interval. Averaging over 3 seconds is a better indication of true top speed, but I've only been able to do that for those runs where I have access to the tracking log. The third column is the peak speed translated to mph.
Mark Harris 21-Feb-2000
Sport| Peak speed |
3-sec average |
Peak mph |
|
| Slalom skis | 123 kph | 115 kph | 76 mph |
| Telemark skis | 71 kph | 67 kph | 44 mph |
| Skate sailing | 42 kph | 25 mph | |
| Kite skating | 40 kph | 24 mph | |
| Windsurfing | 41 kph | 35 kph | 25 mph |
| Kite skiing | 38 kph | 23 mph | |
| Ice yacht | 38 kph | 23 mph | |
| Ice surfing | 26 kph | 15 mph | |
| Sea kayak (surfing) | 21 kph | 13 mph |