CRF converts its ratings used for Time on Distance scoring (expressed in seconds/mile) to the Time Correction Factors (TCF’s) used for Time on Time scoring via the following formula:  TCF=600/(CRF+535), OR TCF=600/(CRF GPH).  For example, a boat with a CRF rating of 72 (or a CRF GPH=72+535=607) would have a TCF=600/(72+535)=600/607=0.988