The White Water River and Creek
‘Whitewater is formed in a rapid, when a river’s gradient increases enough to generate so much turbulence that air is entrained into the water body, that is, it forms a bubbly or aerated and unstable current; the frothy water appears white. The term is also loosely used to refer to less turbulent, but still agitated, flows. The term “whitewater” also has a broader meaning, applying to any river or creek itself that has a significant number of rapids.’
International scale of river difficulty
There are six main “categories” in whitewater kayaking:
There are six categories, each referred to as grade or class followed by a number. The scale is not linear, nor is it fixed. For instance, there can be difficult grade twos, easy grade threes, and so on. The grade of a river may (and usually does) change with the level of flow. Often a river or rapid will be given a numerical grade, and then a plus (+) or minus (-) to indicate if it is in the higher or lower end of the difficulty level.
While a river section may be given an overall grading, it may contain sections above that grade, often noted as features, or conversely, it may contain sections of lower graded water as well. Details of portages may be given if these pose specific challenges.
Class I:
Easy Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.
Class II:
Novice Straightforward rapids with wide, clear channels which are evident without scouting. Occasional maneuvering may be required, but rocks and medium-sized waves are easily avoided by trained paddlers. Swimmers are seldom injured and group assistance, while helpful, is seldom needed. Rapids that are at the upper end of this difficulty range are designated Class II+.
Class III:
Intermediate Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe. Complex maneuvers in fast current and good boat control in tight passages or around ledges are often required; large waves or strainers may be present but are easily avoided. Strong eddies and powerful current effects can be found, particularly on large-volume rivers. Scouting is advisable for inexperienced parties. Injuries while swimming are rare; self-rescue is usually easy but group assistance may be required to avoid long swims. Rapids that are at the lower or upper end of this difficulty range are designated Class III- or Class III+ respectively.
Class IV:
Advanced Intense, powerful but predictable rapids requiring precise boat handling in turbulent water. Depending on the character of the river, it may feature large, unavoidable waves and holes or constricted passages demanding fast maneuvers under pressure. A fast, reliable eddy turn may be needed to initiate maneuvers, scout rapids, or rest. Rapids may require “must make” moves above dangerous hazards. Scouting may be necessary the first time down. Risk of injury to swimmers is moderate to high, and water conditions may make self-rescue difficult. Group assistance for rescue is often essential but requires practiced skills. For kayakers, a strong roll is highly recommended. Rapids that are at the lower or upper end of this difficulty range are designated Class IV- or Class IV+ respectively.
Class V:
Expert Extremely long, obstructed, or very violent rapids which expose a paddler to added risk. Drops may contain large, unavoidable waves and holes or steep, congested chutes with complex, demanding routes. Rapids may continue for long distances between pools, demanding a high level of fitness. What eddies exist may be small, turbulent, or difficult to reach. At the high end of the scale, several of these factors may be combined. Scouting is recommended but may be difficult. Swims are dangerous, and rescue is often difficult even for experts. Proper equipment, extensive experience, and practiced rescue skills are essential.
Because of the large range of difficulty that exists beyond Class IV, Class V is an open-ended, multiple-level scale designated by class 5.0, 5.1, 5.2, etc. Each of these levels is an order of magnitude more difficult than the last. That is, going from Class 5.0 to Class 5.1 is a similar order of magnitude as increasing from Class IV to Class 5.0.
Class VI:
Extreme and Exploratory Rapids Runs of this classification are rarely attempted and often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions. After a Class VI rapid has been run many times, its rating may be changed to an appropriate Class 5.x rating.
River running
Riverrunning (practitioners use one word) is the essential form of kayaking. Whereas its derivative forms have evolved in response to the challenges posed by riverrunning, such as pushing the levels of difficulty and/or competing, riverrunning, of its own right, is more about combining one’s paddling abilities and navigational skills with the movements and environments of rivers themselves. Important to a riverrunner is the experience and expression of the river in its continuity rather than, say, a penchant for its punctuated “vertical” features (e.g. standing waves, play-holes and waterfalls). As for kayak design, a “pure” riverrunning boat can be said to have “driving ability” – a blend of qualities that enables the paddler to make the most of the differential forces in the river’s currents. For example, instead of spinning or pivoting the boat to change its direction, a riverrunner will drive the boat in such a way as to make use of the river’s surface features (e.g. waves, holes and eddylines) thus conserving the boat’s speed and momentum.
Creeking
Creeking is perhaps best thought of as a subcategory of river running, involving very technical and difficult rapids, typically in the Grade/Class IV to VI range. While people will differ on the definition, creeking generally involves higher gradient (approaching or in excess of 100 ft per mi (19 m per km)), and is likely to include running ledges, slides, and waterfalls on relatively small and tight rivers.
Slalom
Slalom is a technical competitive form of kayaking, and the only whitewater event to appear in the Olympic Games. Racers attempt to make their way from the top to the bottom of a designated section of river as fast as possible, while correctly negotiating gates (a series of double-poles suspended vertically over the river). There are usually 18–25 gates in a race which must be navigated in sequential order. Green gates must be negotiated in a downstream direction, red gates in an upstream direction. The events are typically conducted on Grade/Class II to Grade/Class IV water, but the placement of the gates, and precision necessary to paddle them fast and “clean” (without touching a pole and adding 2 seconds to the total time), makes the moves much harder than the water’s difficulty suggests.
Playboating
Playboating, also known as Freestyle or Rodeo, is a more gymnastic and artistic kind of kayaking. While the other varieties of kayaking generally involve going from Point A to Point B, playboaters often stay in one spot in the river (usually in a hole, pourover or on a wave) where they work with and against the dynamic forces of the river to perform a variety of maneuvers. These can include surfing, spinning, and various vertical moves (cartwheels, loops, blunts, pistol and donkey flips, and many others), spinning the boat on all possible axes of rotation. More recently, aerial moves have become accessible, where paddlers perform tricks having gained air from using the speed and bounce of the wave.
Surf kayaking (‘out of category’, but relevant)
Surf kayaking is the sport, technique, and equipment, used in surfing ocean waves with kayaks. Surf kayaking has many similarities to surf board surfing, but with boats designed for use in surf zones, and with a paddle. A number of kayak designs are used, but all are aimed at better using the waves to propel the craft.
Creek kayaks
Creek kayaks are designed primarily for downriver paddling. In general, creek boats are designed to run tight, steep, and technical whitewater (while river runners are designed for down-river speed, catching eddies, and the occasional surf on a green wave). There are a few design characteristics set creek boats apart: Weight, rocker, edge profile and volume distribution.
Weight
We’ll start with the most obvious. Weight is not your friend. Neither kayaking, loading it onto your car, during portage or in a rescue and retrieval situation.
Rocker
The term rocker refers to the curvature or angle of a boat’s hull towards the bow and stern. Boats with longer effective waterline / lower rocker are faster but do not turn as easily as boats with shorter effective waterline. Boats with longer effective waterlines typically are better suited to river-running, where speed is key to moving through large waves and holes and the boat needs to avoid being easily knocked off line.
Shorter waterlines / higher rocker tend to be slower but turn more easily. These boats are better suited to more technical whitewater where manoeuvrability is more important than speed.
The shape of the rocker largely determines how a boat will behave when entering the water from a vertical drop (i.e. a waterfall). The advantage of a progressive rocker is twofold:
first, it takes stress off the paddler’s back when landing larger drops, a
nd second, it allows for more efficient transfer of vertical energy (from falling) into horizontal energy (moving quickly away from the hole at the bottom of the drop).
This makes progressive rocker very desirable on creek boats and less common on river-runners.
Edge
Creek boats with indistinct or soft edges tend to have a “mushy” feel, because they do not engage with water as much as hard edges. They do allow for faster “pivoting” turns, however, as well as smoother moves off rocks, and do not get hung up in boily water as easily. Creek boats tend to have softer edges.
Volume displacement
Boats with proportionally more of their volume distributed into the bow and stern tend to resurface more quickly and under more control. This is the result of increased buoyancy in the bow and stern.
They also tend to be more resistant to burying the bow off ledges, and punching holes (instead they ride over holes).
For these reasons, creek boats tend to have more volume distributed in the bow and stern than river-runners.