Pretty good video here shot on an iPhone 4 at the British Olympic Trials on Friday, 9 March 2012. If you look closely, you’ll notice a flash of red light on one of the center lanes at 0:31, that must be the light signal that Craig Lord mentions here on SwimNews:
The first swimmer home gets one light, the second two, the third three, while the lights do not come on for any other lanes. The effect is immediate, so in a 50m dash in which 0.02sec splits the first three men home, the winner can been identified more quickly by the instant light show on the blocks just above the place that everyone is watching rather than the display on the scoreboard.
