Shanghai-Zhoushan-Shanghai

You can go to the Shanghai South Bus Station where you can find buses for Putuo. These buses will reach Shenjiamen Bus Station in ZS. Upon arrival, you can travel to your destintion there. And the buses takes about 6 hours. The bus fare from Shanghai to ZS is around 130RMB per person.

For the return journey, you can still take a bus at Shenjiamen Bus Station.

Tne best way is to take a tourist bus from Shanghai to ZS. Trip takes a bit more than 4 hours, buses are comfortable, "VIP" class. Bus station in Shanghai is located at Nanpu Bridge, just next to exit from Metro line No 4.