center of each survey area as possible. Data for the cen- 
tral area was obtained for the U.S. Coast Guard Farallon 
Island Light Station, 28 mi west of the entrance to San 
Francisco Bay, and in the southern area for the U.S. 
Navy San Clemente Island Naval Air Station. These 
data were made available by the National Weather 
Records Center, Asheville, N.C. 
RESULTS 
Of the 8,320 cards released over both study areas, 4.5% 
(377) were recovered. This recovery rate compares closely 
with those found by previous investigators using drift 
bottles and drift cards along the west coast of the United 
States (Tibby 1939; Schwartzlose 1964) and near Hawaii 
(Barkley et al. 1964). In the central area, 3.5% of the 
cards were returned, whereas 5.7% of the cards were 
recovered in the southern area. An average 59.8% of all 
cards recovered were found within 1 wk following the 
date of release, and 79.4% were found within 2 wk. The 
percentage of recoveries made during the first week after 
the drop in the central area was 72.1%, and in the 
southern area 52.7%. By the end of 2 wk, the percentage 
of recoveries in the central area was 86.8% and in the 
southern area 75.1%. 
Charts (Fig. la to lh central area, Fig. 2a to 2j 
southern area) giving the date and location of release and 
recovery and the average wind velocity were prepared for 
each quarterly and monthly drifter releases. The average 
wind speed was derived by averaging all values recorded 
during the 2-wk period. The rate of drift and trajectory of 
the card cannot be determined from the recoveries 
because of the lack of information between time of 
release and recovery. Original data to determine the time 
between release and recovery is not available. No 
recoveries were made and no charts were drawn for 
southern area releases in November and December 1965 
and January and February 1966; nor for the central area 
during January 1966. 
DISCUSSION AND CONCLUSIONS 
The patterns of current flow associated with the Cali- 
fornia Current along the North American west coast have 
been examined by a number of scientists (e.g., Tibby 
1939; Sverdrup et al. 1942; Reid et al. 1958; Burt and 
Wyatt 1964; Schwartzlose 1964; Tully 1964). We would 
expect the surface drift in the nearshore areas generally 
to be in agreement with the findings of these scientists. 
Drift card recovery rates probably bear a relationship 
to the amount of shore activity by people. Many areas of 
the coast in the central area are rocky and not easily 
accessible. This, and the fact that the coastal population 
is small, would account for reduced returns when com- 
pared with southern California. The southern California 
coast is easily accessible, except for the island areas, and 
there is a high population level along most of the coast 
and from this a higher recovery rate would be expected. 
Most of the recoveries in the central area were from 
drop stations relatively close to shore. Only three 
11 
recoveries were from the line of drop stations located 
about 25 mi offshore, and none were recovered from the 
outer line of stations, about 50 mi offshore. 
Southern California recoveries were mostly from 
stations near the coast, between the coast and Catalina, 
and the Santa Barbara Channel Islands; few recoveries 
were from the offshore drop stations. 
Drift cards recovered along the coasts of central and 
southern California gave evidence of some surface drift 
toward the east and/or southeast through most of the 
year. Only in December 1966 did neither area have at 
least one return from either direction. Five of the 15 mo 
in the central area and 6 of the 12 mo in the southern area 
had a significantly greater proportion of the recoveries 
from the east and/or southeast than from all other direc- 
tions combined. 
Off the central area, little evidence of a strong David- 
son Current can be observed along the open coast during 
the late fall, winter, or early spring months [Fig. la, 1c 
(March), 1g (November), 1h (December, February)]. 
Only in December 1964 (Fig. 1c) does evidence of the 
coastal countercurrent exist, with recoveries from off 
Bodega Bay from drift cards dropped near the San Fran- 
cisco light vessel. Schwartzlose (1964) had indications 
from his work that an eddy flowed counterclockwise dur- 
ing the summer between San Francisco and the north 
edge of Monterey Bay. In July 1965 (Fig. le), off Half- 
moon Bay and south of Point Reyes, some of the 
recoveries indicated a northward flowing coastal current 
during this period. During the remainder of the year, 
most of the recoveries showed drift to the east and/or 
southeast. 
In the southern area between Point Conception and 
northern Baja California, an average 69% of the drift 
cards recovered had moved in an east and/or southeast 
direction. These observations reflect the combined in- 
fluence of northwest winds and the relatively permanent 
southerly flowing current reported by Schwartzlose 
(1964) off the southern California and Baja California 
coasts. 
Evidence for the gyre south off southern California was 
found during the late spring and summer (Fig. 2b, 2e, 2h, 
2i). Some of the returns from coastal areas were 
recovered northeast to northwest of release points and 
these recoveries were most evident along the coast from 
San Diego northward and offshore to the San Clemente 
and Catalina Islands and the Los Angeles area. During 
these months Tibby (1939) reported that south flowing 
offshore currents return along shore as the north flowing 
Southern California Countercurrent. Forty percent of the 
returns from the August 1965 (Fig. 2i) releases drifted 
north or northwest nearly 90° from the prevailing winds 
flowing toward the east-northeast. Returns from the 
December 1964 (Fig. 2c) drift cards lend support to the 
conclusion by Reid et al. (1958), that the northerly flow- 
ing countercurrent associated with the large eddy off 
southern California is present in some measure through 
the late fall and winter. 
