A whitewater river is any river where its gradient and/or flow create rapids or whitewater turbulence.
whitewater
Holes[edit]See also: Swiftwater rescue and CanyoningHoles, or "hydraulics", (also known as "stoppers" or "souse-holes" (see also Pillows) are formed when water pours over the top of a submerged object, or underwater ledges, causing the surface water to flow back upstream toward the object. Holes can be particularly dangerous—a boater or watercraft may become stuck under the surface in the recirculating water—or entertaining play-spots, where paddlers use the holes' features to perform various playboating moves.
Eddy Lines // Located between the eddy and the main current, the eddy line is a swirling seam of green and sometimes white water. Eddy lines vary in size based on the size of the water column, the gradient of the section, and the obstacle creating the eddy. Often containing boils and whirlpools, eddy lines can spin and grab your watercraft in unexpected ways, but if used correctly, they can be a really playful spot. Full slice and half slice boaters are able to perform tricks like stern squirts and cartwheels, but nobody uses eddy lines as well as squirt boaters, who use the swirling water and crossing currents to dance below the surface of the river.
Waves[edit]Waves are formed in a similar manner to hydraulics and are sometimes also considered hydraulics. Waves are noted by the large, smooth face on the water rushing down. Sometimes, a particularly large wave also is followed by a "wave train", a long series of waves. These standing waves can be smooth or can be breaking waves (also called "whitecaps" or "haystacks").
