SeaChange also released details last week of a specialist military shark repellent unit for army and naval divers and downed air force pilots.

SeaChange chairman Rod Hartley said specialised Shark Shield prototypes currently were being field-tested for Australian military personnel and trialled by defence and civil authorities in Asia and Europe.

"Military divers often are more vulnerable to shark attacks than recreational water users because they may be unable to choose when and where to go in particular waters," Mr Hartley said.

Shark Shield is widely used by commercial divers in Australia – including abalone and scallop divers in SA.

Police divers in almost every state use Shark Shield, as well as other Australian government agencies.

The device works by surrounding the user with an electrical field of a particular patented wave-form that impacts on the shark's central nervous system and becomes intolerable for the animal when it gets too close.

SeaChange Technology believes the electrical wall can be adapted for much wider application where signals can be emitted to protect marine farms, beaches and small bays.

It would be five years, SeaChange believes, before the larger repellent is in place.

"We have been contacted by many divers who said their lives have been saved by this technology," Mr Hartley said.

"We really believe it can become as valuable to water safety as the seatbelt and airbags have to car safety." =