Welcome to the forum. A bit of info like what parts of Aust you are likely to visitand how long would probably help. I'm having a guess but I suppose that you are a Kiwi. A bit about yourself and type of detector as well. Are you after gold or just treasure/coin hunting?
Welcome to the forum Dirt fishing dave.
As mentioned above, it's a very big country, mate! Might be an idea to narrow it down to a city you're visiting.
Seven days isn't very long to do much travelling for prospecting with family visits in the mix too, so I'd say it will have to be close by.
Are you after gold or other? We could help you with a bit more info.