The mean longshore currents in the surf zone were measured along more than 1 km of a beach. These measurements were compared to a theoretical model of the system in which the current depends on the angle of incidence of the incoming waves and the longshore variation in both wave height and breaker angle. A wave refraction programme was used to compute the values of wave height and breaker angle every 100 m along the beach from the measured values of wave period and deep water wave direction. In general, the large scale variation of currents along the beach was well described by the theory. However, superimposed upon these large scales of motion were fairly regular, small-scale circulation cells which are probably associated with edge waves at the incoming wave frequency.