I AM AUSTRALIAN DO I NEED A VISA FOR 1 DAY VISIT ON A CRUISE SHIP TO SHANGHAI

My wife and I are visiting Shanghai on a cruise ship on 1st November 2015 for 1 day. The cruise ship arrives in port at 6am and departs at 10pm for Okinawa Japan the same day. As we will be in China for less than 24 hours and do not intend disembarking the cruise ship whilst in port as we have been to China previously, can you please advise if an entry permit is required?