Trust elmo to beat me to the post button, as he says it's a big body of water, roughly 10km diameter, and the eastern side is very isolated.
So what sort of windsurfing are you interested in?
Most of the regulars, are part of the "GPS Team Challenge" and we're into speed sailing, so want flat water.
Some of the better sailors have hit 40kts here.
If you search Fangman's posts you should find something, he made a google map with lots of marks and comments on it.
Also here,
www.gpsteamchallenge.com.au/pages/guides/hardies_rocksIs a diagram of the rock garden markers, between Novara and alpha land. Unless it's very high tide and you have a sub 20cm fin, stay well clear of this area.
Basically there are lots of places to sail, depending on wind direction and tide.
There are a few places relatively smooth up to about 25kts, once over that most of the spots start getting choppy.
The wind on the estuary is probably 5kts lighter than the ocean.
In winter there's a lot of very cold rain run off from the hills and the estuary is fairly shallow so looses it's heat quickly. So expect water temperature to be much colder than the ocean.
In summer, the reverse is true, in the shallow areas the water heats up and can be very warm.
There are Crabs that nip and cobblers that sting, these can be very unpleasant to say the least. There's also plenty of sting rays but I haven't heard of any agro from them as yet. There's been shark sightings as well, but so far no attacks I know of, plenty of dolphins to give you a scare though, they'll try and surf your bow wave, and can pop up right beside you without any warning.