Whitewater difficulty scale

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The whitewater difficulty scale is used to assess the difficulty of whitewater for canoeists and rafters . Artificial installations in rivers ( weirs , fish ladders ) are not white water and are not assessed. Nevertheless, artificial installations can be life-threatening.

The International Canoe Federation (ICF) differentiates between six levels of difficulty, numbered with Roman numerals : From WW I "not difficult" to WW VI "limit of navigability".

Definition according to the German Canoe Association and ICF
Degree I. II III IV V VI
in the word not difficult (also: not difficult) moderately difficult difficult very difficult extremely difficult Limit of navigability
view free free passages clear passages Passages not immediately recognizable, exploration mostly necessary Exploration essential Generally impossible to navigate, possibly navigable at certain water levels, high risk
water regular current,
regular waves,
small surges
irregular current flow,
irregular waves,
medium surges,
weak rollers , eddies, press water
high, irregular waves,
larger waves,
rollers, eddies, press water
high continuous gushes,
powerful rollers, eddies, press water
extreme surges,
extreme rollers, eddies, press water
Riverbed simple obstacles simple obstacles in the power train, smaller steps individual blocks, steps,
other obstacles in the current train
Blocks offset in the stream, higher steps with back suction tight blocks, high inclines with difficult entrances and exits

Sometimes the Roman numerals are replaced by the Arabic numerals 1–6.

Water ratings according to the whitewater difficulty scale are subject to constant change. As advances in driving technique and further developments in equipment make it possible to navigate increasingly difficult waters, the assessment is regularly postponed. Deviating from similar difficulty scales (e.g. in climbing ), which provide for upward extensions, evaluations according to the whitewater difficulty scale always depend on the time of the evaluation.

Standing or gently flowing water is called tame water . The transition to WW-I is fluid.

Practical navigability and dangers

With increasing water flow - the flow rate in cubic meters / second - of a flowing water, its flow speed essentially increases and waves and other flow phenomena are generally more pronounced, which increases the degree of difficulty. However, if, with rising water, more evenly sloping bank areas or detours reach a manageable water depth or swells are rather leveled or waste is flooded, a body of water may also become more navigable as the water flow rises, provided the passages offering relief are also easily accessible. A reference for the current water flow is provided by measuring a nearby level - as the water level in centimeters.

Large flotsam such as logs, tree trunks or whole trees are particularly dangerous - typically during floods , or ice floes or an ice surge in winter. Dangerous obstacles can lie above water in the form of tree branches, ropes and bridges with insufficient headroom or under water, barely recognizable in time, such as the remains of dead pilots, things in which the boat and man can get caught, such as the wire loop of a fence or one in the ground Shopping trolley thrown into the river. Particular natural dangers are the undercurrent of the rock, the water flow through a bottleneck with stone blocks and a flow running down through a gap through an annular or channel-shaped constriction, the siphon - all with the potential of being pressed, held and jammed under water. Weir, inlet rakes to a power station, canalization through a pipe are man-made; buoys and locks in waterways.

Also relevant for the practice of navigability is the presence of a good exit point - in short, exit - from the water with the possibility that people and also the boat can easily reach a path from there to get further. A difficult body of water can sometimes be avoided by broadcasting.

Boats - construction, damage, safety devices

For a folding boat made of wooden strips with a rubber-textile skin stretched over them, the massive impact on a gap in the rock was already dangerous, a point in the rock, a nail or the end of a wire could tear the skin and had to be glued.

Inflatable boats were initially based on cotton and natural rubber. Fibers, elastomer and molding have been further developed so that inexpensive inflatables can withstand more chafing and point loads.

After that, heavier kayaks made of GRP (glass fiber with polyester and / or epoxy resin) are very abrasion-resistant when they come into contact with the ground, but broke in the middle of the access hatch when buckled.

Plastic boats produced by whirl sintering in the hollow space from granulate of the thermoplastic polyethylene (PE) bend partially elastically very far without breaking and can more or less recover at the bend in the heat of the sun, almost taking on their original shape again.

Boats made of more modern fiber-reinforced plastics with Kevlar or carbon fibers are particularly light (for getting off and transferring) or particularly unbreakable.

Since Topolino, shorter kayaks have been built for rodeo / acrobatics.

To be on the safe side, kayaks are built with larger hatches (Big Hole) than before (Keyhole), which allow easier disembarking in an emergency; and with pull-in handles. A support made of a foam block between the keel and deck at the level of the knees of the paddler can prevent him from becoming trapped if the boat bends in the middle.

Web links

Individual evidence

  1. LEISURE SPORTS> Actions> Canoeing the family sport> Equipment and safety: Is canoeing also suitable for my family? kanu.de, DKV, accessed October 3, 2019.