Using CAFS, the fire-stopping effectiveness of first-arriving fire scene resources — equipment, personnel and water supply — increases up to five times. In some fire situations, this allows crews to turn a defensive operation into an offensive attack. The use of CAFS has reinvented the limits of what a given total water supply and/or water delivery rate can do. Rather then protecting exposures and letting a fire burn unhindered, CAFS often is successful in darkening the main body of a large fire.