A lot of foam
This is called "sea foam", a strange occurrence where various organic particles from the ocean get whipped together with air and arrive on the shore.
In this case, the huge quantities of sea foam in the Australian town of Mooloolaba were caused by the rough weather from a nearby cyclone.
It's such an odd-looking thing that some people seeing the images for the first time might think it was a hoax.
It's not, but something tricky does occur in the following video:
Sunshine Coast Floods