What the guide is looking at

A rapid reads from the top: the V of smooth water pointing into it is the tongue, and the raft goes down the tongue. The white below is where the water is fighting itself. The guide is looking for the line through the white that keeps the raft straight, and calling the paddle strokes that hold it there. When you hear "get down", that is the one instruction that is not optional.

Written from the verandah, with a cup of chai going cold.