The steering oar was used to throw the boat one way or another in rapids, but it was mainly on the side oars that we relied for steering.
In our boat Powell looked ahead, and gave orders "left" or "right," referring not to the direction in which he wished to go but to the oar which we were to pull with reference to our left or right not his.
"Steady" meant to let the boat take her course.
N.Galloway, who has since made several descents, goes through rapids stern foremost.

He can thus see how to guide with the oars..