Join a club like the Storm Riders (or others) in NSW for about $60 or $200 and this covers your membership affilitation and insurance. I am still confused about the entitlement to sail as a guest at other clubs part which is only covered for the expensive membership.
Then you can also pick a sail number from the available list... Members of AWA affiliated bodies have the right to a number at no cost. www.windsurfing.org/sailnumber_staterules.htm
For LOC this year you need to be a member of any AWA affiliated club or any state association. Our preference is to get people engaged with WWA as we have a great calendar of racing and wave sailing coming up but if LOC is your only event, you can buy a one day membership via the WWA web site