in SSW-SE winds go to 5 mile, follow the gravel road going to the conservation park until you find a sort of round turning space with a water level sign.
In westerly direction go to 3 mile, there is a sign for a camping area, enter, then turn right .
If you have a 4wd or you like risk you can drive to the spit, which works in all directions, but maybe wait until someone else is there for that trip.
other tip: stay at least 50m from the islands, there are some rocks and star pickets close to them