254 



the limiting factor. Given a shoreward transport, the rate 

 of disappearance of coliforra organisms then becomes the 

 all-important criteria by which conditions at the beach must 

 be judged. This intimately involves the velocity of trans- 

 port . 



The general statement has been made that current velo- 

 cities in Santa Monica Bay are relatively slow, but this is 

 not sufficient. Because current velocities are of critical 

 importance, it is necessary to analyze them in more detail. 



Current measurements involving the use of current meters, 

 current crosses, and drogues have shown that outside of the 

 littoral zone velocities of the order of 0.6 MPH are rare, 

 those of the order of 0.4 are infrequent, and the usual 

 velocity is 0.2 MPH or less. Current meter observations 

 showed the highest velocities in the Malibu region and near 

 the Redondo Submarine Canyon. Drogues have given values as 

 high as 0.6 MPH in the general region of the proposed out- 

 falls, but it is to be noted that these observations were of 

 drift of a few hours, and the net transport toward the beach 

 would probably have been at a lesser speed over a period of 

 twelve hours or more. 



The maximum current velocity obtained from drift card 

 recoveries was 0.78 MPH. However, of the 1,803 cards recovered 

 to date, only those from two cruises showed velocities greater 

 than 0.58 MPH, and the number of individual cards travelling 

 at that speed were few indeed. On only 4 cruises were maximiun 

 velocities in excess of 0.31 MPH. Moreover, almost without 

 exception those high velocities were obtained from stations 



