Finding "Bliss"
Great Mackerel Beach is on the very Northern boundary of Sydney and is only around an hour or so from the centre of Sydney. It is water access only but is easily accessed from Palm Beach by ferry, water taxi or barge.

Just drive to the Palm Beach Wharf opposite Barrenjoey House and find a park in the non-restricted areas in the neighbourhood. You can also get the B-line to Mona Vale and then either the 199 Bus or the Keoride (on demand bus - just download the app) to Palm Beach Wharf.
At the wharf you have a choice of either "Myra" the ferry (Fantasea.com.au) or the Blue Water Taxi (operated by Guy) 0415 408 831.
On Friday nights there are ferries directly across to Mackerel at 6pm, 7pm and 8pm.
If you want to be taken right to the front of Bliss on the beach just head down to the Palm Beach Boat House (a short drive further) and get the barge operated by Barrenjoey Boating Services (barrenjoeyboating.com.au) right to the beach in front of Bliss. For those "Home and Away" tragics you get the barge from "Alf's Bait Shop"