Hi mate, there's a few foiling from either Kanahooka or Illawarra Sailing Clubs. There's also a few of us who foil on St. Georges Basin and Jervis Bay which are about an hour south of Lake Illawarra.
I'm not going to say there's no weed however there's nothing that will really ruin your experience.
Hope you have a great time and it will stop raining enough to get some wind