Rapids - Features & Hazards

• Waves
  Waves can be either smooth or turbulent. Some waves, especially the large ones, have subsequent wave trains, which are a prolonged series of waves. Usually perpendicular to the water current on the river, waves can flip off crafts, including the passengers.


• Holes
  Holes, which are formed when water from below goes upstream, can be serious white water hazards. An indication of the presence of hydraulics is foamy current that draws backwards. Examples of dangerous hydraulic types are weirs and underwater ledges.


• Undercut Rocks
  A common river feature, undercut rocks are rocks the bases of which have been eroded over time. These rocks usually have pillows or pressure waves. Undercut rocks pose extreme hazards for water current can pull rafters and trap them underneath.


• Strainers
  When objects obstruct the flow of larger objects on a water stream, they act as strainers. Objects that can become strainers include fallen trees, bushes, debris, and industrial scraps. Avoid getting pulled under the water by climbing over the strainer straight away.


• Sweepers
  Sweepers can be obstructions in the river for they can act as strainers, blocking the passage of objects. Sweepers include uprooted trees that fall or bend toward the river. Sweepers can pose risks for paddlers who traverse rivers with fast-moving currents.


• Sieves
  A sieve is a narrow space between two obstructions such as rocks where water flows through. A rafter or even a whole boat can be pinned against a sieve and may be trapped underwater. Sieves can be tricky especially when fully submerged in water.


• Eddies
  An area located behind an obstacle such as a rock or a boulder, an eddy can range from being mild to turbulent. Mild eddies can be good resting places while turbulent eddies can be very unstable and are least recommended for parking Rafts.