The shark shield is a repellent, but you don't spray it on (how cool would that be). Rather, it emits an electric field that 'induces spasms in sharks snouts'. Apparently, it doesn't hurt the shark or the environment. I read that it only works when it's stationary - I take it that 'it' means the shield is stationary and not the shark.
You'd need nerves of steel to resist the urge to flee with a shark bearing down on you with a toothy grin. But I suppose you've got nothing to lose (or should that be win) either way.
If you've been following my blog as thousands around the world have, you'll have read my numerous shark posts from last season. In February through to April there were many shark sightings and several serious attacks in Sydney waters - in the harbour at Woolloomooloo, at Bondi Beach and at Avalon on the northern beaches.
Two of the attacks took place before dawn and the Bondi mauling in the evening, which is when sharks are hungry.
Simple solution: don't swim at dawn or at dusk when sharks are on the prowl for tucker.
Expect more shark posts as the days grow warmer and crowds of potential shark bait flock to Sydney's beaches AND THE OCEAN SWIMS SEASON GETS UNDERWAY...
Never smile at a crocodile and don't swim in the dark with a Great White Shark.