Originally Posted by
drewguy
If you have only a 1 hour layover, you should not need to pass through HK immigration on your way to Shanghai - you'll be a transit passenger that doesn't need to pass through. (By way of comparison, I've often gone to Shenzhen via ferry - never deal with HK immigration).
Just to clarify the above - although I never took a ferry from HKIA to China, I believe that passengers should stay landside. I don't think passengers can re-enter immigration and get to the ferry once landside.