I like the Ramp at Mooney Mooney,
if you like to explore the the area around Bar Point, north of Berowra Waters and Milsons Point.
The Ramp at Brooklyn (Parsley Bay) is good as well and you can explore the area aound Dangar Island and the middle of the Hawkesbury, I like the new Jetty at Parsly Bay and it's easier when it's windy.
But maybe the best option for you is Apple Tree Bay down at Bobbin Head.
You save a lot of time going down from the Pacific Hwy at Turramurra.
Cowan Creek is good fisching and calm water, I like Jerusalem Bay and from there it's under 10 min to the Hawkesbury.
If you go up to Brooklyn it takes another 30-40 min from Turramurra.
The only thing is the 11 bugs for National Parks at Bobbin Head, but that the 11 bugs you save on fuel