In any case, Wyong/Central Coast Council has a photograph and a little more detail of it, here.
Several alternative locations have been proposed, but that pic establishes that it was close to Blue Lagoon Caravan Park. It's only the alignment of The Entrance Road that appears in doubt.
There is one source that places Bateau Bay airstrip at The Entrance, in the grounds of what is now the Entrance High School. That's probably a confusion of schools. It's possible, but it's very close to the township itself and on sloping ground. It's not consistent with the image, anyway.
The alternative school site at Bateau Bay proper is flatter and better in every way (for an airstrip), barring some 'swampiness'. In accord with the image above, it may have only partly have been on the school site, in any case.
Bateau Bay, New South Wales at AllExperts
* Bateau Bay was once home to an airstrip known as The Entrance Airstrip. The site of The Entrance Airstrip is now within the grounds of The Entrance High School *Much more likely is a slightly more southerly location, including the sports fields and possibly part of the school site. It is mentioned by a Gosford Aeromodeller: "The first time I spotted radio control models was in 1972 at the old The Entrance airstrip near Bateau Bay. This area is now occupied by sports fields and a High School. They drew a big crowd on Sundays because of the nearby Entrance road. The club however was soon on the move because permanent flying fields were hard to find, even in those days. By the time I had decided to join they were no longer at Bateau Bay and for a time I was unable to locate them."
So in any case it was closer to Bateau Bay than The Entrance, putting it down on the flatter land to the south on what is now at least partly Tuggerah Lakes College (formerly Bateau Bay High School). This site fits with my recollections as well - although I didn't come to the coast a lot in the late 60's early '70s I could have sworn I saw an old strip down on the flat near the main junction (now a roundabout).
See the comments below, placing the airstrip immediately south of the current school grounds.
Checkout my list of Sydney and surrounding airstrips and airports.