Current
River water flows downstream. Fast water moves the boat farther each second. You have less time to steer.
water → → → boat
Channel
A channel is the path water flows through. It can be wide or narrow. In this game, narrow parts have faster water.
Bend
Water flows at different speeds across a bend. In this game, the outside is faster. The inside is calmer.
Eddy
Water can slow down behind a big rock. It may swirl in a loop. That swirl is called an eddy.
Relative Motion
The boat moves through water. The water also moves past the shore. Both motions add up to the trip you see.
Vector
A vector shows speed and which way things move. An arrow can show the flow. Another can show the boat.
current ↑ + steering → = motion ↗
Ground Speed
Ground speed is the speed you see from shore. The boat moves through water. The flow adds to that motion.
Distance = Speed × Time
If speed stays the same, use distance = speed × time. For example, 2 meters each second for 5 seconds gives 10 meters.
Anticipation
Steer for where you will be next. The flow keeps pushing your boat. Plan your turn before you reach a gate.
Erosion
Fast water can wash soil off the bank. This is called erosion. The outside of a bend often loses more soil.
inside: deposit ) outside: erode
Deposition
When water slows, sand and small stones can drop to the bed. They build up there. This is called deposition.
Point Bar
A point bar is a pile of sand and small stones. It often forms on the inside of a bend. Water is slower there.
Wetland
A wetland has wet soil for part of the year or longer. Reeds grow there. Fish, birds, and bugs may live there.
Riparian Vegetation
Riparian means beside a river. Trees, shrubs, and grass grow there. Their roots grip soil. Their shade helps keep water cool.
Habitat
A habitat is a place where a plant or animal lives. Rocks, logs, and calm water make homes for many kinds of life.
Bank Stabilization
Roots help hold the bank soil in place. They can slow the loss of soil. Bare banks may wash away more easily.