Monday, April 1, 2002		On Hardware

Evading Jaws

A graphic shows how an electronic field is emitted from a shark shield in this undated graphic. An Australian firm unveiled an electronic shark repellant unit last week that attaches to a swimmer's leg and emits an electronic field to ward-off sharks. The electronic shark repellent unit is a miniature version of cumbersome anti-shark pods used to protect triathletes in Sydney Harbour during the 2000 Olympics and worn by abalone divers.

AN Australian firm unveiled an electronic shark repellant unit that attaches to a swimmer's ankle and emits an electronic field to ward-off sharks.

The electronic shark repellent unit is a miniature version of cumbersome anti-shark pods used to protect triathletes in Sydney Harbour during the 2000 Olympics and worn by abalone divers.

The personal anti-shark unit weighs 450 grams (1 lb) and has a battery life of two hours. A slightly larger unit for scuba divers weighs 590 grams (1.3 lb) with a battery life of four hours.

The swimmer's anti-shark unit will retail for about Aus $ 700 ($240), said SeaChange Technology Pty Ltd that has miniaturised the original Shark pod technology developed by the Natal Shark Board in South Africa.

SeaChange said testing of the electronic shark repellant units in waters off South Australia and South Africa, both renowned Great White habitats, showed sharks were repelled at about two to three metres (six to nine feet) from a swimmer.

The diver's pack repelled sharks at four to five metres (12 to 15 feet).

The electronic field affects the shark's nervous system through sensitive receptors near its snout. An initial mild discomfort increases as the shark approaches the field until it causes intolerable muscle spasms.

"It puts out a very precise electrical field that sharks perceive because of a hunting sense they have," Jerry Kleeman, managing director of SeaChange, told reporters.

"So as sharks get closer to you they will veer away very rapidly as it becomes uncomfortable for them, but it doesn't cause them any lasting harm. It also does not impact on any other marine creatures or humans."

SeaChange is working on electronic shark repellant units that can be used to create a safety zone off the back of boats and yachts and a larger version for beach protection.

"Apart from protecting human lives, the beach protection units would enable the removal of existing net and hooking systems that are responsible for the slaughter of a range of marine life, including protected species such as whales, dolphins, turtles and dugongs," said the company in a statement.

SeaChange sports a variety of investors, including Adelaide-based Gerard Industries and Playford Capital, joint owned by software giant Microsoft Corp, computer management firm Electronic Data Systems Corp and the Australian government.

— Reuters