One zone neutral or 
Agree in Opposed in rip current the other 
Direction Direction North or South 
Surf Zone Number 97 30 36 
compared with 
Outside Per Cent 59.5 18.4 emi 
Breakers 
The velocity measurements are based on 49 measurements inside the breakers 
and 22 measurements outside. These give a median velocity of 0.55 knots in- 
side and 0.23 knots outside, that is, a ratio of 1 to 2... The faster 
average currents outside the breakers than at Scripps pier are probably re- 
lated to the larger agreement in direction in currents inside and outside the 
breakers at Crystal pier. It is also possible that the small group of ob- 
servations has not given an average picture. The agreement of currents in 
direction inside and outside is far larger than between the same two zones 
at Scripps pier. 
The larger number of north and south currents may not have much signifi- 
cance. Some weekly observations along the beach near the pier over the 
course of a year showed slightly more south than north currents. 
Current Meter Studies at Scripps Pier 
It is difficult to compare the Dahl-Sverdrup current recordings at the 
end of Scripps pier made during much of the period between 1937 and 1940 with 
the daily observations of recent years. The recordings were made by a current 
meter suspended 8 feet below the surface and operated electrically. The re- 
cords were averaged by E. G. La Fond for each hour, each day, and each month 
but the results were never published and some of the data are missing. The 
records indicate that the currents are predominantly slow as was the case in 
the recent observations, Daily averages show that the net current was north 
on 182 days and south on 212 days which is approximately the same as for our 
observations. Velocities of north and south currents are similar. Examina- 
tion of records indicates that the current direction frequently changed during 
the course of a twenty-four hour period and often when the current was pre- 
dominantly in one direction there were two periods in the course of the 
twenty-four hours when it was reversed. These reversals, however, did not 
take place with any clear relation to the tidal cycle. On many days the 
current was continuously in the same direction. It is difficult to be sure 
whether or not the tide is an important factor in these currents. 
Acknowledgments 
The writers desire to express appreciation for the help given by R. L. 
Wisner, Ruth Young, and J. R. Moriarty in making many of the observations. 
Suggestions in connection with the work were kindly supplied to us by Mr. 
D. L. Inman and Dr. R. S. Arthur. 
