I have dived in the waters around Sydney for almost 25 years and although I have spent in excess of 5,000 hours underwater I have never seen, what I call a dangerous shark (a shark capable of inflicting injuries which could kill a diver).
It has been over 50 years (January 28, 1963 ) since the last fatal shark attack in Sydney Harbour. There has never been a fatal attack by a shark of anyone one on scuba.
As a diver you will see a number of sharks while diving around Sydney but the vast majority are the Port Jacson Shark and it close cousin the Crested Horn Shark. The teeth of the Port Jackson Shark are plate like and used to crush and grind the shells of the mollusks and echinoderms.
The second most common shark you will see while diving around Sydney is the Wobbegong. When I started diving you would see a Wobbegong on most dives but they have been fished to such a level that you now will only seen one on every 20-50 dives. Wobbegongs are bottom-living sharks grow to impressive sizes. Wobbegongs have not been known to attack humans. If provoked wobbegongs will nip dives with the bite somewhat similar to a dog bit. So it is advisable not to annoy them by poking them or pulling their tails.
The third common shark is the Grey Nurse although theses are fairly rare and normally you need to go to specific locations such as Magic Point if you want to see them. The Grey Nurse is the most scary looking shark you are likely to see, this is due to their relatively large size and sharp, protruding teeth that point outward from their jaws, however they are quite docile, and are not a threat to humans: their mouths are not large enough to cause a human fatality. We organize regular shark dives with the grey nurse sharks at Magic Point.
With it been over 50 years since the last fatal shark attack in Sydney, and the rarity of seeing dangerous sharks, it is obvious that the risk of having a shark attack while diving in Sydney is extremely unlikely. Most diver go looking for sharks and our biggest disappointment is we don’t see them often enough.