Shark Shield makes it safe to go back in the water

Both units weigh approximately 1kg and the closest a shark is likely to approach a user equipped with the dive unit under normal conditions is 4-5 metres, with the general-purpose model effective at up to 2-3 metres.Because it is based on electrical conductivity, the Shark Shield cannot be used in fresh or estuarine waters where the lack of salt reduces the water's ability to conduct electrical. The antenna itself may cause twitching in the surface muscles of the skin if the user touches or comes into close proximity with it but the electric field is more like to surround the body rather than penetrate it and causes no health problems.

The Shark Shield has been developed from the larger Shark POD, a device used successfully over the past six years by abalone and specialist divers as well as the Australian military. The technology has been extensively tested in the most shark-infested waters of the world such as Neptune Island in South Australia and off Cape Town in South Africa. In an example of non-human testing, bloody meat was strapped to a surfboard along with the Shark Shield and thrown into the ocean near a seal colony - sharks were repelled 100% of the time in 5000 tests according to of SeaChange chairman Rod Hartley.

The shark-repelling technology is also being adapted for kayaking, jet-skiing, sailboarding and boat protection. Lifejackets incorporating the Shark Shield are also in planning and larger versions of the Shark Shield that offering beach protection are already being investigated the governments of Western Australia and Queensland. Because the Shark Shield does not repel other form of marine life this would have the added advantage of allowing the removal of indiscriminate net systems which often trap other creatures such as dolphins, turtles and dugongs.

Though there is, on average, just one shark attack death in Australia each year (compared with eight scuba diving accidents and more than 300 drownings), fear of sharks is believed to inhibit many people from taking up aquatic activities - according to surveys conducted by PADI, the world's largest scuba diving accreditation and training agency, fear of sharks is the number one reason people do not learn to dive. Combine this with the fact that an estimated 30 million plus people worldwide either dive or surf and you have a gizmo with amazing market potential - as well as something that will positively impact on the lives of many people.

The Shark Shield is available from www.aquanaut.com.au - the dive unit costs AUD$695 and the general-purpose unit costs AUD$665 and no - there is no guarantee.