Ever wondered what it was the removes fins and skin in the Mandurah estuary?
This and many other rocks are out there just waiting to relieve you of A)your fin, B) the back of your board and / or C)the ability to move and /or breathe.
BEWARE sailing/kiting in the estuary, particularly at other than high tides. Around this rock are many others. If you are catapulted/ land from a boost you may well hit one and
the image below shows that this rock is about 300mm above the bottom. Just because there is enough water to sail/ kite there may be very little above this and other rocks.
This is in the middle of the area speed sailers use