The defensive swim:
When there are eddies downstream of a short rapid, roll onto your back and keep your feet up so they crest the surface, which will keep your feet from getting trapped beneath a rock. Never try to stand. Angle your body toward an eddy at 45 degrees (feet pointing toward the eddy you want) and backstroke across the current into the eddy.
The aggressive swim:
For long stretches of continuous whitewater, roll onto your stomach with head pointed downstream. Keep your feet high and your head out of water and use the crawl stroke to aggressively traverse the fast current. Look for an eddy downstream and swim toward it at a 45-degree angle. Try to reach the eddy as high as possible to give yourself time to break the eddy line, which can act as a fence to keep you out of the eddy’s calm water. To break the eddy line, cross it at a 90-degree angle and reach into the calm water with your upstream arm, pulling aggressively through the water.