Shark shocker

Surfers should soon have a safer ride, thanks to a newly marketed idea from SeaChange Technology in Australia (WO 03/026410). The surfer straps a cuff round an ankle. The cuff trails a plastic tail with two metal electrodes a metre apart along its length. Every 20 milliseconds, a battery and pulse generator in the cuff send 2 millisecond-long pulses of electricity to the electrodes. This creates a pulsing field in the water behind the surfer, which sharks can’t stand. SeaChange says this significantly reduces the chances of an attack from the rear.