Technology originated in South Africa I believe and the Aussies knew a smart idea...
A note of warning though: according to the latest info, the device should be turned on at all times in the water, not just when a shark shows aggressive behaviour. This establishes the boundary from the onset. Put another way, within the favourite Great White areas - False Bay, Cape Town for instance - you will probably not see the one that bites you, not with viz often around 5-10m. So, you might not have a chance to turn it on. :10: Amazing animals, to be treated with respect...