What are the benefits of a carbon-fiber paddle for whitewater kayaking?

In addition to the reduced weight, carbon fiber paddles are a bit more rigid than the traditional fiberglass and resin paddles frequently used by whitewater paddlers.  This extra rigidity allows more of the energy exerted by the paddler to be transferred to the blades.  The result is faster turns and greater agility, all things any paddler needs when navigating more technical stretches of the river.