Visa requirements

My wife and I (both Australians) are taking a cruise of Japan, starting and ending in Shanghai.
We wonder if we can make use of the 72 hours or 144 hours visa free allowance.

Draft Itinerary
June 01 Arriving by air to Shanghai from Australia
Staying in a hotel in Shanghai (under 72 or 144 hours which ever applies)
June 03 at 5pm Cruise departing from Shanghai
June 04 to 10 cruising Japan (part 1)
June 11 at 7 am back in Shanghai but staying on the ship
June 11 at 5 pm departing on the same ship to Japan (part 2)
June 12 to 18 cruising Japan
June 19 at 7 am returning to Shanghai and disembarking
Staying in a hotel in shanghai (up to 72 hours)
Flying back to Australia from Shanghai
Based on the above itinerary, would you please tell us if we require a visa.
And if not what limits do apply - 72 hours or 144?
Thank you
Antonin Aujesky (Mr) and Alena Aujesky (Mrs)