See the operator's web site for contact information.
I'm sure they do other things as well, but the trip we took involved flying to Cottage Point restaurant for lunch, buzzing the bridge and the opera house on the way back (with the permission of air traffic control, of course, as this gets a bit close to the international airport's airspace). The cost, whilst obviously non-trivial, was actually quite reasonable.
The pilot pumping water out of the floats before flying back to Sydney. Don't worry, this is standard procedure.
Lunch at Cottage Point. While it looked like nouvelle cuisine this was deceptive: the plates were very large so we ended up with normal Australian sized helpings (ie too much food).
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Sydney | |||||
You can also see Sydney Harbour from the decks of the Bounty, a replica made for the film.