Shark Island is one of the larger islands on Sydney Harbour that have been reserved for public use, and can be visited todayfor picnics and other events. Shark Island also functions as an animal quarantine area and a naval storage depot. It is a naval landmark, as it presents danger to passing ships and boats that may land on the rocky and shallow waters that surround it.
Shark Island is located in Rose Bay and if you are planning on catching a water taxi to the island for a private visit, it is best to arrange your departure from Rose Bay itself. A bonus about Shark Island, over the other harbour islands, is that a ferry service is also in operation to the Island, with voyages leaving several times each day from Circular Quay.
This means you don't need to pay as much as you would if you were hiring your own water taxi, however you will still need to make your reservations before you visit.