Editing Whitewater (section)

=== Eddies ===
[[Eddy (fluid dynamics)|Eddies]] are formed, like hydraulics, on the downstream face of an obstruction. Unlike hydraulics, which swirl vertically in the water column,  eddies revolve on the horizontal surface of the water. Typically, they are calm spots where the downward movement of water is partially or fully arrested—a place to rest or to make one's way upstream. However, in very powerful water, eddies can have powerful, swirling currents that trap or even can flip boats{{citation needed|date=October 2020}} and from which escape can be very difficult.