Pittwater is approximately 1 hour drive north of Sydney CBD and has a wide cruising ground surrounded by the bush of Ku-ring-gai Chase National Park.
This area is a quieter area to cruise than the busy Sydney Harbour, and great for a weekend getaway. Over the busy Christmas/New Year period there may be minimum hire.
You can sail/cruise around into the Hawkesbury River (subject to swell height) where you will find plenty of quiet bays. Yachts can go up to the railway bridge at Brooklyn, and cruisers further.