Good morning , 72 hour Visa exemption

I am a NZ citizen born here and have booked a cruise from Shanghai leaving 30 march 2019 , I arrive at 7am at Shanghai and the ship leaves at 8pm the same day , do I need a visa of any kind ? . The ship ( Celebrity Millennium ) leaves China for South Korea and returns 4 days later for a 2 and a half day visit to Beijing , then leaves going on to Japan . Can you please place my mind at rest and confirm that the 72 hour twov exemption does apply , and a visa is not required . Thank you .