The current forecast looks like promising SE winds on Friday.. Fingers crossed it stays like that.

I don't think I've ever windsurfed in SE winds before, where would you go around Hobart? (say within an hour's drive)

Cremorne lagoon is the hot place to be , on a good se seabreeze youget about 15 people out.
Cifton beach also good if you want surf, river if you want... well the river

Park/Carlton Beach can be good if it's a true SE, in theory it should be cross-on however most south easterlies tend to more SSE.
Marion Bay (boneyard) has been known to produce good wavesailing conditions in strong SE winds.