Fascinating patterns floated on the water surface at the edges of some pools where the Derwent River’s movement was slower.

The creation of these white swirling patterns has been explained as follows: The natural tannins from button grass plains and other vegetation seeps into the soil and, with rain, runs off the hills into creeks and rivers. The washing of water over the rocks creates a slight foam. When in deep pools the foam gets pushed into back-waters and the continual slow movement of the water creates the lacework.  Mesmerising to watch the gradual changes.