River - rating scale
RIVER - RATING SCALE
Recommend: ''The complete whitewater
rafter'' - Jeff Bennett
None system is not exact; rivers do not always fit easily into one
category, and regional or individual interpretations may cause
misunderstandings. It is no substitute for a guidebook or accurate
first - hand descriptions of a run.
Paddlers attempting difficult runs in an unfamiliar area should
act cautiously until they get a feel for the way the scale is
interpreted locally. River difficulty may change each year due to
fluctuations in water level, downed trees, geological disturbances,
or bad weather. Stay alert for unexpected problems!
As river difficulty increases, the danger to swimming
paddlers becomes more severe. As rapids become longer and more
continuous, the challenge increases. There is a difference between
running an occasional Class IV rapid and dealing with an entire
river of this category. Allow an extra margin of safety between
skills and river ratings when the water is cold or if the river
itself is remote and inaccessible
International Scale of River Difficulty
Class I:
Easy.
Fast moving water with riffles and small waves. Few obstructions,
all obvius 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 missed by
trained paddlers. Swimmers are seldom injured and group assistance,
while helpful, is seldom needed.
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 stainers 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.
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" moves above dangerous hazards. Scouting is
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.
Class V:
Expert. Extremely long,
obstructed, or very violent rapids which expose a paddler to above
average endangerment. 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 mandatory but
often difficult even for experts. Proper equipment, extensive
experience, and practiced rescue skills are essential for
survival.
Class VI:
Extreme. One grade more
difficult than Class V. This runs often exemplify the extremes of
difficulty, unpredictability and danger. The consequences of errors
are very severe and rescue may be impossible. For teams of experts
only, at favorable water levels, after close personal inspection
and taking all precautions. This class does not represent drops
thought to be unrunnable, but may include rapids which are only
occasionally run.
Every single classification could be marked by plus or minus. So
the class III+ is more demanding than the class III , and the class
IV- is slightly less demanding than the class VI. This
classification could be even more thorough as far as the class V is
concerned. The class V goes from V1(less demanding) to V 10
(extremely demanding).
It's necessary to remember that all attempts of
clasification are a bit subjective and that we need to decide for
ourselves what our capabilities are.