In reply to springfall2008:
> Thanks for all the replies, it sounds like either walk in from the Introductory Rocks or abseil in from the car park side
You can descend easily and more directly to a point just N of the Hollow Rock tunnel, cutting out the longer northward loop of going via Introductory Rocks. It's about 100m N of the toilet block. Even if you abseil in or use the longer approach first time, I'd go back up that way; then you'll know where it is.
... by the way, I don't recommend the Waterpipe Bay scrambling descents with novices/children - they are fairly easy technically, but exposed and can be dirty.
Post edited at 16:33