Pure information: From shanghai south railway station you can take a bus to putuo (zhoushan) for 150 RMB at zhoushan you grab a ferry ticket for 30 RMB and a ticket to enter the island at 160 RMB (passports required also). once you're on the island there are no didi's but the island itself is small enough to walk to the north in around 2 hours and there are shuttle busses, though i didnt use them. you'll need to buy a return ferry ticket to zhoushan for your trip back on the bus.there is also a direct ferry from shanghai to putuoshan and from putuoshan to shanghai once per day but this will take you 12 hours compared to the 4 hours or so on the bus. as a final piece of infornation, yes you are actually allowed to swim in the sea here. i went around 30 meteres out having a bit of a play and a swim, this was at baibusha (hundred step beach) with lifeguards on jetskis for safety. i hope this helps you plan your trip as i had to do my own research and if you dont speak any chinese im sure it could be a challenge!very much worth it howevet,