Awareness- Having a broader scope of vision that encompasses not just one self but the surroundings and other paddlers on the river. 

C.F.S.- Cubic feet per second. A unit of water flow used to indicate the volume of water flowing per second past any given point along a river. 

Eddy Out- Term used to describe leaving the main current and entering an eddy. 

Ferry- The act of crossing a section of river without going downstream by maintaining a boat angle. 

Gauge- Measures river volume in feet (physical height of the water in the river), cubic feet per second (CFS) which is the amount of water passing that particular spot on the river. A visual representation of this is to imagine that the water in the river is made up of basketballs thus the CFS in this case would be the number of basketballs passing a given spot in a second. A higher CFS means more water in the river. Can also be measured in meters per second (MTS). 

Gradient- The “steepness” of a river, measured in feet of elevation loss per mile of river. 

Horizon Line- Usually indicates that the river gradient has dropped implying rapids, falls, or drop ahead. 

Peel Out- Term used to describe leaving an eddy and entering the main current; bow catches the main current and quickly swings the boat downstream. 

PFD- Personal Flotation Device. Otherwise known as a life jacket. 

Portage- To carry the boats around a rapid or obstacle. 

Put-in- The starting point of a river trip where boats are put into the river. 

River Left- The left-hand side of the river when looking downstream. When downstream looking upstream it is on your right. 

River Right- The right-hand side of the river when looking downstream. When downstream looking upstream it is on your left.

Safety Talk- A pre-trip talk to learn about safety on the river to maximize awareness. 

Shuttle- The most dangerous part of the trip. Driving between the put-in and take-out. One-vehicle shuttles require logistical foresight using options such as biking, walking, hitchhiking, etc., to return to the put-in. 

Sweep Guide- This guide stays at the rear of the trip. 

Take-out- River access where a trip ends 

Trip Leader- A Guide designated to oversee the smooth running of a trip. 

Boil- This is a water feature created when water churns upward and creates an elevated region in the river. 

Bony- A run or rapid requiring lots of maneuvering because of the abundance of obstacles, mostly rocks. 

Confluence- The point where two or more rivers meet. 

Drop- An abrupt descent in a river. A pitch. 

Downstream “V”- Describes the shape of the current when it passes between two obstacles. The V points downstream and could be further delineated by wave trains. 

Eddy- A river feature formed by an obstacle in the downstream flow. A well formed eddy will have a defined eddy line and a calm pool behind the obstacle. Being able to “catch” or stop in these calm pools is one of the keystones of whitewater paddling. 

Eddy Line- A current differential between the upstream current of the eddy and the downstream current of the main flow of the river. 

Haystacks- A large standing wave caused by deceleration of current. 

Headwall- Steep cliff where the main channel of the river drives against it at a 90-degree angle. 

Hole- Where water flowing over a rock or other obstacle flows down, then back onto itself in an eruption of whitewater. 

Hydraulic- Also known as a hole, is a river feature where water drops over a obstruction (rock ledge or a rock) into deeper water on the downstream side. This causes water on the surface to be drawn back toward the rock or ledge. This can be a potentially hazardous feature but it could also be a feature used for playboating. Low head dam’s are the most dangerous example of a hydraulic. 

Pillow- Pillow is the water that builds up on the upstream side of an obstruction. 

Rooster Tail- Spray of water that explodes off a submerged rock or obstacle. 

Standing Waves (also known as wave trains) – Standing waves are associated with constricted areas of water most commonly called Downstream V’s. Water can only be pushed out downstream so fast so the water pushes upward into waves. 

Strainer- 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. A serious hazard! 

Tongue- The smooth “v” of fast water found at the head of rapids. 

Undercut- Overhanging rock or ledge with water flowing underneath it. A serious hazard! 

Upstream “V”- Found on either side of a downstream “V” which represents the shape an eddy makes. Obstacles on both right and left will create downstream “V’s” and those obstacles create eddies. 

Waterfall- A major drop in a riverbed, usually over six feet in height. 

Class A- Lake water, still, no perceptible movement. 

Class I- Easy, smooth water, light riffles, clear passages, occasional sand banks and gentle curves. The most difficult problems might arise when paddling around bridges and other obvious obstructions. 

Class II- Moderate, medium to quick water, rapids with regular waves, clear and open passages between rocks and ledges, maneuvering required. 

Class III- Moderately difficult, numerous high and irregular waves, rocks and eddies with passages clear but narrow and requiring experience to run, visual inspection required if rapids are unknown. 

Class IV- Difficult, long and powerful rapids and standing waves, holes and boiling eddies, powerful and precise maneuvering required, visual inspection mandatory, advance preparations for possible rescue work important.

Class V- Extremely difficult, long and violent rapids that follow each other almost without interruption, river filled with obstructions, big drops and violent currents, extremely steep gradient, rescue preparations mandatory. 

Class VI- Extraordinarily difficult, paddlers face constant threat of death because of extreme danger, navigable only when water levels and conditions are favorable, every safety precaution must be taken.