From jbshack's newspaper clipping:
WA Fisheries said..
Stay out of water if sharks have been spotted in the area
Like Brighton/Scarborough/Trigg for three days in a row and counting?
WA Fisheries said..
Stay close to shore (within 30m of the water's edge)
Nope. That would be a rarity for me. Even pushing it when bodysurfing.
WA Fisheries said..
Don't go in the water alone (stay in groups)
I prefer to surf alone or with as few as possible rather than 50 of my best mates. Unless it's at my local(s), where I can deal with a crowd. Many, many times this winter I was outside earshot range of other people.
WA Fisheries said..
Avoid water temperatures lower than 22C
So don't surf from late autumn to mid spring, longer further south?
WA Fisheries said..
Avoid water depths of greater than 5m when swimming or surfing
I would do this at beach breaks, but lots of reef breaks have > 5m around. And Ken Crew and Ben Linden definitely weren't in > 5m of water.
WA Fisheries said..
Avoid swimming after heavy storms, or in low light (dusk and dawn)
Heavy storms are the only driver of swell in Perth, so count winter out. I reckon this applies more to bulls though.
Low light - I surf a lot at dawn and dusk. Before or after work. I can't take three hours out in the middle of the day but I can before/after work.
WA Fisheries said..
Avoid swimming if there are seals, dolphins, whales or baitfish nearby
Seal colonies all over the place now. So rule out most rocky coastlines within a few hours of Perth. See dolphins all the time. Whales all September/October. Baitfish, always.
Following these guidelines would mean essentially giving up surfing and swimming.
And the probability thing doesn't apply. Plenty of Australians go for a few splashes a year in the shoreline. Not many spend hundreds of hours a year.