River Terms

River Terms

Learn these terms to talk like a rafting guide (or at least know what your rafting guide is talking about).

White Water Rafting Scale

Scale – Whitewater is classified on a scale from I to VI. A description of this is given below:

Class I

Easy, flat water. No problem. Take your grandmother.

Class II

Small rapids with clear, wide channels. Take a timid friend.

Class III

Good-sized rapids with waves and boulders. Chances of maneuvers inside the rapids are great. Get a guide!

Class IV

Intense rapids. Plan on maneuvers, hazards, big waves and tight boulders. For those seeking a challenge.

Class V

Intense and violent. Long rapids, drops, extremely tight channels, and hazards. Get a good guide!

Class VI

Don’t do it. If you do, say your final prayers first.


Cubic feet per second is a volume of water measure, which is commonly used to describe most rivers. It is measured by a water gauging device.


Protected from the main current, these smooth sections of water are found behind obstacles (e.g., boulders or bends in the river).

Hole, Hydraulic or Reversal

When water falls over an object (e.g., a rock or ledge), the falling water creates a depression. Surrounding surface water rushes to fill in the depression and forms a hole.


An obstacle in the river that allows water to pass through, but not a person or boat (e.g., a tree with its limbs partially submerged).

Wave Train

A series of standing waves perpendicular to the main current.