I might get uncharacteristically energetic & scan some old pix of a much younger (and sillier) Jamjar racing motorcycles around Surfers....got one taken from under the bridge that shows the speedo on the Kwaka GPz900R proddy bike pegged on 240 + kmh.
Aeroplanes used to frequent the strip on race weekends, giving joyflights to racegoers. Local Aeromed helicopters were not in vogue then but during a couple of international events (Swann Series and International Touring Cars) there were private medivac helicopters stationed there.
I believe the japanese golf resort next door bought the circuit simply to shut it down, so they weren't disturbed while wacking little white balls......
