User:MadiSalinas1/sandbox

Rapids - link to article. Underline parts are the additions

(Continue from the 2 paragraph)....Rapids cause water aeration of the stream or river, resulting in better water quality. The ecosystems in rapids must be able to adapt to survive the currents produced by the river, such as those that support freshwater fish.

Rapids are categorized in classes, generally running from I to VI. Class I waters are the simplest, least hazardous form of rapids, that move with the flow of the current. A Class V rapid may be categorized as Class V.I-V.IX. An example of a rapid that has the class V criteria is the Futaleufú river. While Class I rapids are easy to navigate and require little maneuvering, Class VI rapids pose threat to life with little or no chance for rescue. River rafting sports are carried out where many rapids are present in the course. Rapids can be used by the public in recreational ways, such as whitewater rafting.