Below is a picture of foam and granite along the coastal rocks just west of Petrel Cove on the southern Fleurieu Peninsula.
It was made on a day after the big storm in early May. Though the storm had passed the seas were still surging and they were too rough for the surfers. The 2 metre high waves dumped, rather than rolled into the shore.
The picture above refers back to this earlier picture of foam as well as to this one. This is what the littoral zone looks like during, or just after, a big storm from the south west. The foam quickly vanishes.