A friend just called me to say that she had heard that a Whale Shark was swimming in Botany Bay. "No way" was my initial reaction. Apparently members of the Abyss Scuba Diving encountered the fish this morning and have posted images on their Facebook account.
The species has been previously recorded from Botany Bay, in fact one stranded there in 1964 (see lower image).
In Australia it is known primarily from northern Western Australia, the Northern Territory and Queensland. It is also recorded from scattered localities in New South Wales, Victoria and even the western Great Australian Bight.
Post script (29 April 2011)
The fish was estimated to be 4 m in length. Carl Fallon and companions from Abyss Diving couldn't believe it as their boat passed by "a very large shark" at about 11 am on April 2011. As quickly as possible they returned to the spot where they saw the shark, but it had 'disappeared'. After searching for a few minutes, the shark actually swam up to their boat where it remained for 3 to 4 minutes. It circled the boat several times, even raising an eye out of the water to watch the occupants, before swimming away.