Attached is a diagram that depicts how various whitewater features are formed as a rock is gradually covered by rising water. This is fundamental to understanding how to read water and how to read the river when kayaking, canoeing, or rafting.
These images are a side view from water level.
The DVD river runners edge has a water reading segment that nicely demonstrates how this works. For teaching, the sketch works well because it takes away ambiguity.
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