I have had sharks swim by me while fly fishing on Great Keppel Is many years ago. Unless its a great white, I dont think sharks see us as prey. You may get an angry bull shark bite someone in murky water but other shark species seem to leave us alone.
People have been taken in Sydney in knee deep water a few times....... Especially middle harbour, you'd have death wish getting in the water there, I think Bull Sharks have been the main culprit too.
Some gruesome pictures in this article so don't read it if eating breakfast.......