This figure I derived from the data available at the Mathematics Genealogy Project
Windsurfing video captured from a helmet mounted GoPro Hero HD camera.[^1] The final gust lifts the front of the board causing the bailout. The GPS hit 54 kph at the time of the bailout. Formula board with a 8.4 m2 sail.
Another video with headup display.
A bit of signal processing on my backyard astro captures (sorry about the music).