When capsized and floating on your back in a swift river current, how should you position your feet?

When being carried away by a swift river, it is best to place one's feet facing downstream of the river.

This allows the person to see any where they are going, reducing the sense of panic that is involved in the situation. Moreover, it gives them a visual of the obstacles that are in place of the flow and avoid them, and if a collision can not be avoided, then a collision with the feet will do far less damage than a collision with the head.