Low Water Flows below an expected average. More rocks and obstacles may show, rapids become more technical. Eddie Water flowing upstream behind a rock or other obstacle. Eddies often provide a safe place to get out of the current. Where the water flowing upstream passes the water flowing downstream.
Water flowing through a shallower, constricted, or steeper section forms a rapid.
Where water flowing over a rock or other obstacle flows down, then back onto itself in an eruption of whitewater. Laterals A wave or hole peeling off an obstacle at an angle. Haystack A wave in a river formed by obstacles on the river bottom, where the wave stands still relative to the bank. Strainer, Sieve An opening or openings where water can flow through, but a solid object such as a person or boat cannot. Usually formed by trees on the banks, or by rocks on top of one another with water flowing through them.