Don’t be afraid to go back into the water?

An electronic anti-shark unit small enough to be attached to a swimmer’s ankle has been developed by an Australian firm.

The SeaChange Technology device emits an electronic field that is specially designed to affect the shark’s unique nervous system without impinging on other marine life.

An initial mild discomfort increases as the shark approaches the field, and eventually develops into intolerable muscle spasms.

The ankle unit, which is slightly heavier than a mobile phone, is a miniature version of existing anti-shark pods and repels sharks at around 6-9ft from the swimmer. It weighs just over 450g and has a battery life of approximately two hours.

A slightly larger and heavier version with double the battery life, which is designed for scuba divers, is also available .

SeaChange Technology is now hoping to develop the unit so that it can be incorporated into life jackets.