If a shark is sighted by the Westpac chopper it will hover, and will sound a shark siren. The chopper on a weekend will normally radio the nearest Surf life saving club to clear the water as well.
During the week, the Uni fixed wing plane also has a shark siren and if people are in real danger, police will be called to clear the beach.
You will find often the fix wing and chopper will do holding circuits over Henley jetty and Glenelg north, just flying around in circles, they are normally waiting for clearance from the airport to past the runway.
Rumors are that the sharks are here early this year, in the past they haven’t normally ventured up this part of the coast until early December. The fix wind and chopper normally see about 7 sharks in the metro water, only counting sharks larger than 7ft. under that it’s hard to see from 500ft.
Last week, 3 sharks were sighted, only 1 was in close enough to warrant any attention.
The main thing is that if surf life savers are asking you to get out of the water, listen to them, and if you hear the shark siren, just chill on the beach. The chopper will normal hover low, and bank right, the sharks hates the vibrations this makes in the water and the sharks move out of the area pretty quick.
But don’t worry it’s only been 2 years since are last shark attack!!!!
. Several rather large finned friends move up the coast around Sept, Oct and hang around till March, April (give or take a couple of weeks). They chase the snapper that have moved up the gulf to breed. So in all reality, they are never to far away, helicopter or no helicopter. Sorry to be the bearer of bad news. The tricks are, land all your jumps, don't loose your board to far out, change direction in a hurry out deep and don't look down or behind you, ignorance is bliss. 
