The Batemans Bouy managed by Manly Hydraulics is measuring significant wave heights (Hs) of 6m plus
Hs is is the wave height of the 1/3rd highest wave in a given time group (not the famous 7th wave).
The height of the highest 1% of waves (H1/100) is approximately equal to 1.67 times Hs, and a theoretical maximum wave height (Hmax)
So the chart below shows you the Hs and also the calculated Hmax that might happen in a 1 in 100 set of waves.