Macau Visa question

Hello.
I plan on visiting friends in Macau in a couple of months. I understand Australians have a 30 day stay allowance. But I plan to stay in Macau for maybe 2 months. Is it possible to hop on a ferry to Hong Kong after 30 days and come back to Macau in a couple of days to restart the 30 day stay? Or will I have to apply for an extension? Thanks