Is a visa required for a 14 day cruise from Shanghai to Hong Kong

We are flying standby from San Francisco to Shanghai, we will stay overnite then board our ship. During the cruise there will be a 2.5 day stop in Bejing. Then from there another 4 stops in Japan, Korean and then Hong Kong. We will overnite on the ship in Hong Kong and then leave the next morning standby back to San fransico. The question is: Do we need a visa for this cruise intinenary? I can't seem to get a straight answer from the cruise line.