The man speaking to us had a full grey head of hair, slicked back by the salt water, remnants of the recent dip in the ocean dripping slowly onto his face. He tells us he has been swimming in these waters- this little plot of beach and ocean- for twenty years.
"Only the second or third time, I reckon." He pauses, exhales and proceeds on a long winded story about close encounters of the whale kind. It's the shark part I'm interested in, the shark part I want to come back to. I shift my weight between my sand-packed zebra coloured flops, waiting for a moment to ask again.
Only 500 meters earlier, treading water just off the shore break, the endurance swim group we stumbled upon (invitation via exceedingly friendly lifeguard at the local pool) paused before carrying on their Sunday morning swim to Big Beach. The consensus in the group was quick and unanimous. Due to the murkiness of the water we must swim back immediately. The group was vague and unwilling to explain to us mainlanders why the cause for alarm. 
"We don't swim in this water because of the risk of shark attack. It goes up substantially when they can't see you, and because this water is so murky, that's a factor. They don't understand you're not prey. So to keep our arms and legs, we only swim when we can see the bottom." The man grinned. (Later he tells me how often a swim about-face has occurred since he started wintering here). 

I swam a  record pace back to the beach.