Shark drones make for a safer summer but no guarantees

Before last summer, Australians often perceived shark predation as an out-of-sight, out-of-mind risk endemic to remote communities.

Then came the string of attacks, two of them fatal, at beaches off the nation's most populous coastline.

The most recent involved young Sydney mum Leah Stewart, who barely escaped with her life after being bitten at Coogee in June.

If it wasn't already the case, the assault slammed home the danger lurking in waters where there had once been little need to worry.

Less than a year earlier, 57-year-old surfer Mercury Psillakis was killed in an attack at Dee Why, on the city's northern peninsula.

So began a summer where the risk seemingly posed to five million Sydneysiders was splashed across websites and evening news bulletins.

In response, the NSW government launched a $120 million world-leading shark mitigation program, which would be rolled out over two years and feature near constant daylight monitoring of Sydney beaches.

It also includes two new listening stations tracking tagged sharks in the harbour for the first time, and smart drum lines to bait and release potential problem animals.

The government also shelved its own environmental concerns to install 51 traditional mesh nets at beaches between Newcastle and Wollongong.

Expanding drone monitoring has been broadly welcomed, including by Mr Psillakis' brother Mike who says the technology could be truly lifesaving.

"I believe that if there was a drone on the days my brother and Leah were attacked, my brother would be with me and Leah wouldn't have those injuries," he tells AAP.

Forced to fend off the four-metre great white with a flurry of punches, 35-year-old Ms Stewart underwent a series of operations, including the amputation of her left arm.

The drones are not without room for error, however, with operators required to manually observe a screen and make decisions on when to evacuate beaches.

Marcel Green, who runs the NSW Department of Primary Industries shark program says it is a matter of when, not if a serious attack occurs while a drone is in the air.