One from my archives - any idea what it is?
It's called Nature's Cappuccino - down at Circular Pool in the South West of WA, the saponins, that come from plants as they break down in the water, bubble and foam and they pass over the rapids in the river.
Down near the river's edge at Circular Pool just below the rapids there is a little landing on which you can stand and take photos or just get close to the river. While standing there with my 'sister' JB and taking a series of photos a little puff of wind came from nowhere and blew foam all over us. I don't think we have laughed so much as at that moment - lovely memories of a great trip.