It's not news that Charlize Theron is made of strong stuff - she watched her mother shoot her father, AND she dated Sean Penn for a prolonged period. So the fact that she nonchalantly swum in shark infested waters in her native South Africa isn't exactly a surprise. Especially as it took her family 6 hours to drive to the seaside. You're not going to sit in a car for 6 hours to go to the beach and then not get into the water...
In the below video, the actress brings up the recent shark attack in St Jeffrey's Bay involving pro-surfer Mick Fanning (possibly in haste to change the subject matter from Jimmy Kimmel's infectious bodily fluids) and fondly recalls a time when they used to get called out of the water by the life guard who'd seen some sharks, and were then casually let back into the water once the sharks disappeared from sight...