Technically, the Grand Canyon does not have "rapids" in the traditional sense. Rapids form from rocky, turbulent shallows. The Colorado River in the Grand Canyon is deep and powerful, with major drops at waterfalls and constrictions—not classic rapids.
Grand Canyon uses a 1–10 scale (unique), not I–VI. Lava Falls = 10. Most are 3–7.
Grand Canyon "rapids" are pool-drop type: calm pools between steep, short drops caused by tributary debris fans. This differs from continuous rocky rapids in steep mountain streams.
Rafters navigate 225 river miles with ~80 named rapids—each a distinct hydraulic event.