"In the surf" (where the sand meets the water), southern end of Bondi Beach. (Access beach from Notts Avenue or Campbell Parade). (Google Pin - https://goo.gl/maps/5PSjAmVReGR2)
The maximum number of people at the ceremony is 20. That is 18 guests (including children above 5 yrs) and the 2 of you. At this location, this can NOT be increased.