Discussions on Seabreeze and examining Google Earth lead me to check out Lake Macquarie at Swansea.
Today there was a strong westerly in NSW. In my experience westerlies are quite gusty, especially at spots easily accessible by windsurfers on the north side of Sydney. So its difficult to find a place with consitent westerly winds and flatish or flat water.
We went up to Swansea and had a look. The wind was very strong and more importantly very consistent. We were there for around half an hour and during that time the wind did not stop blowing. I'd guessimate it was over 30 knots in the gusts and didn't go below 25 knots. It was too much wind for me as I'm still recoving from back surgery. There were a few kiters out and they were going really well.
We travelled around the lake after this and saw some windsurfers at Warners Bay. The wind was noticably guster and weaker there.
The water was pretty flat too. Out in the lake the water was pretty choppy. Closer to shore the water was flat, not mirror smooth but with small ripples. There are sandbars around reducing the chop. The water is clear and weed free.
The tides are an important factor with some current.
It took us a bit over an hour to get there from Hornsby and the same time back so it doesn't take too long to get there. Below are a couple of photos of the lake at Swansea.
If the wind backs off a bit I'll probably give it a go tomorrow.