Rapids are small regular waves. The passage is clear and
easy to recognise and negotiate. Care may be needed with obstacles like
fallen trees and bridge piers.
Rapids have regular, medium sized waves (less than 1 metre),
low ledges or drops, easy eddies and gradual bends. The passage is easy
to recognise and is generally unobstructed although there may be rocks
in the main current, overhanging branches or log jams.
Rapids with fairly high waves (1-2 metres), broken water,
stoppers, and strong eddies, exposed rocks and small falls. The passage
may be difficult to recognise from the river and manoeuvring to negotiate
the rapid is required.
Difficult rapids with high, powerful, irregular waves,
broken water, often boiling eddies, strong stoppers, ledges, drops and
dangerous exposed rocks. The passage is often difficult to recognise and
precise and sequential manoeuvring is required.
Very powerful rapids with very confused and broken water,
large drops, violent and fast currents, abrupt turns, difficult powerful
stoppers and fast boiling eddies; numerous obstacles in the main current.
Complex, precise and powerful sequential manoeuvring is required. A definite
risk to personal safety exists.