<p>Whitewater paddling is obviously an exciting yet dangerous activity. The main concerns lie in the water and the water features themselves. It is therefore crucial that the whitewater kayaker, canoeist, and rafter know not only the terminology for whitewater river features but also how to identify them as well as be able to communicate them to other whitewater paddlers. Here is a list of the most common river features and hazards that whitewater kayakers, canoeists, and rafters must know.</p><h3><a href="https://www.thoughtco.com/the-whitewater-classification-system-2555685" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">Whitewater Classification</a></h3>At this point it is important to note that rivers and rapids are described based on the whitewater classification system. For example, a whole river can be classified as <a href="https://www.thoughtco.com/the-whitewater-classification-system-2555685" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">class III</a>. An individual rapid or river feature can be classified as say <a href="https://www.thoughtco.com/the-whitewater-classification-system-2555685" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="3">class iv</a>, independent of the river classification. It is important to know and understand the whitewater classification system.<h3>Rapid</h3>Whitewater rivers consist of rapids. A rapid is a series of whitewater river features that are strung together. While it could refer to just a wave or two, the word rapid generally refers to 3 or more connected river features in a section of river.<h3>Continuous Whitewater</h3>When a kayaker uses the word continuous to denote a section of river or the river itself it means that there are no breaks in the action. Like river classification, rivers and rapids can also be called continuous independent of each other.<h3>Pool</h3>A pool of water is a section of river with no rapids and with very slow moving water in it. It usually refers to a smaller area that consists of this characteristic.<h3>Flatwater</h3>Flatwater is a section of river that contains no rapids. This does not however mean that there is no current. The river can still be moving rather quickly and still be flat.<h3>Wave</h3>A wave is a whitewater river feature that is formed due to a boulder or underwater ledge that forces the water rushing over it to push up at the surface. As a wave increases in size it will actually “break” or fall over causing the froth that gives whitewater its name.<h3>Wave Train</h3>A wave train is a series of waves in succession. Wave trains usually consist of three or more waves. The effect of paddling through a wave train is often that of riding a roller coaster.<h3>Hole or Recirculation</h3>A hole is a whitewater river feature that forms as the river flows over an obstruction that is usually near or above the surface of the water. As the water pours over that boulder it causes a recirculation on the other side. This recirculation, or hole, is a frothy and aerated feature that actually flows or pushes upstream. This means that kayaks, canoes, and rafts can actually get stopped and stuck in holes. As the river flows downstream the hole will be “holding” the paddler as it pushes him or her upstream.<h3><a href="https://www.thoughtco.com/kayaking-big-shoals-on-the-suwannee-river-2555489" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="4">Eddy</a></h3>An eddy is a section of water that forms behind exposed boulders and on the sides of rivers around bends. As the river flows by these areas it creates an effect that causes the water in the eddy to flow up stream. Eddys are usually calm spots that kayaks, rafts, and canoes can sit in while the rest of the river flows downstream.<h3>Drop and Ledge</h3>There are ledges on rivers which serve as a shelf to the next level of the river. Ledges up to a few feet are also called drops because the kayak, canoe, or raft drops to the next level of the river.<h3>Waterfall</h3>A waterfall is a ledge or drop that is more than just a few feet. While this is subjective, drops of over 10 feet are usually called waterfalls.<h3>Line</h3>Very generically, a line in whitewater is the path that the paddler will want to take through any rapid, wave, hole, or other river feature.