I dragged a couple of threads out for you by searching for "reef island" where I have not yet sailed. These basically boil down to "the map looks like there should be somewhere but there itsn't anywhere so go to Inverloch.

www.seabreeze.com.au/forums/Windsurfing/Victoria/Avonsleigh-where-is-the-closest-sailing-spot
www.seabreeze.com.au/forums/Windsurfing/Victoria/spot-advice-needed-please

But given that you say "beginner/intermediate" I read "If it all goes wrong I'd like to be blown back onto the beach".

If you can make the distance, you will probably have a great time at Inverloch, where there will be a heap of windsurfers, flat water and hopefully if the forecast for tomorrow is correct, it will get windy.

Thanks Guys... the yacht club and boat ramp at cowes proved to be good for flat water in a northerly but plenty of weed