If you are likely to be participating in more than one overseas event, or will travel to other overseas ports following the event, your will need to register your vessel.
Registering your vessel grants Australian nationality to a ship and can also benefit you if you wish to sell your yacht in the future, as good title to the vessel is assured.
You will need to provide confirmation of your registration to Australian Customs prior to granting clearance to depart. International ports will also need some form of national registration prior to granting formal clearance into that country.