Walk on Water opens with a powerful kayaker tearing through rapids with astonishing ease. The film waits a long while to reveal that its subject, Greg Mallory, is paralyzed from the waist down. Mallory, who lost the use of his legs after a skiing accident, has found in kayaking a warrant for living life normally, a source of joy in the wake of a terrible tragedy.

His fellow kayakers understand that, for those inclined toward this sort of adventure, choice does not enter into the equation — he simply must be on the edge. They go to incredible lengths, often to their own great inconvenience, to help Mallory get into the water. Their payment is the same as ours: the awe of watching Mallory navigate the river as though he were controlling its very flow, even as his kayak is whipped around by powerful currents. On the water, his disability melts away.