Killer whales have never been known to attack humans in the wild. Even in pools they have really only ever attacked out of frustration or direct anger towards trainers.
I was once in the water of Secret Harbour (back in its glory days of just dunes and beach) when a pod swam past maybe 100 mtrs away. Really funny to see as there fins were jet black and huge. We thought they must have been mutant Dolphins at first but when the Helicopter started to film them we thought something else. Anyway my mate and i made the evening news

Worst part was we had ditched his granddads funeral as it was too depressing so we were completely busted by our parents