Refrain from drinking creek or river water no matter how clean it appears. Carry out whatever you carry in. Should you capsize, try to stay with your boat and swim it to shore, making certain that you're on the upstream side of the craft to avoid getting pinned between it and rocks or willows. Easy Moving water with few riffles and small waves. Few or no obstructions.
Correct course is easy to determine.
Medium Fairly frequent, but unobstructed rapids. Course generally easy to recognize. Some maneuvering is required. Difficult Numerous rapids with high and irregular waves. Narrow passages that often require complex maneuvering.