International River Grading System
| Grade 1 | Easy |  |
Slow to medium flowing water with very small, regular waves or riffles. Relatively few obstacles, with an easy path to find and follow. |
||
| Grade 2 | Medium |  |
Rapids are straighforward with medium sized, regular waves. The path through the rapids can be clearly seen from the water and is often indicated by well-defined chutes of Vs of water. There are some obstacles that require manoeuvring around, but paddlers with a good command of basic strockes can easily miss them. |
||
| Grade 3 | Difficult |  |
| Rapids have moderate, irregular waves and strong currents. Manoeuvrin is required to follow the preferred route. Small to medium size stoppers may have to be negotiated. The route is difficult for inexperienced paddlers to see and scouting is advisable. Suitable for experienced Whitewater paddlers with the ability to roll an advantage. (Penrith Whitewater Stadium is an example) |
||
| Grade 4 | Advanced |  |
| Rapids have large waves and powerful confused currents. Drops are big and stoppers can be large and unavoidable. Fast manoeuvres may need to be made. The route is not clear, and scouting may be needed. Suitable only for very experienced whitewater paddlers with consistent skills and reliable rolls. | ||
| Grade 5 | Expert |  |
Extremely long, obstructed or powerful rapids. Rapids may contain very large unavoidable drops, waves, and stoppers and turbulent, unpredictable currents. Fast and accurate manoeuvring is necessary. Eddies may be very small, turbulent and scarce. The route is complex and scouting is highly recommended. Suitable only for expert paddlers, who are willing to accept the higher level of risk. Rolling in adverse conditions is essential. Swiming is very dangerous. |
||
| Grade 6 | Extreme |  |
Rapids are extremely technically difficult, powerful and unpredictable. They are rarely paddled and if they are paddled successfully they are usually downgraded to Grade 5+. The river cannot be paddled without severe risk to life. |
||
