A dynamic model is developed to represent rip currents on open and sandy beaches, based on a multiple regression adjustment between the estimated longshore current speed and the rip current speed mea sured near Duck, North Carolina at the US Army Corps of Engineers Field Research Center. The speed of the longshore current and the tidal current are calculated at incipient breaking and their correlation is established with the speed of the observed rip current, corresponding to the same wave parameters and with the use of the program computer CurveExpert Professional 2.6.3 of the year 2017, a multiple regression equation was obtained to calculate the speed of the rip current, having the best correlation as the independent variable. It was found that larger waves and wave directions closer to the normal to the shore produced stronger rip currents and that strong flows parallel to the shore correspond to lower rip current intensities. The developed model is consistent in calculating the speed of rip currents on open and sandy beaches, with more than 70% accuracy for the locality where instrumental observations are available.