7. Bottom topography within Bolinas Lagoon was obtained from soundings made in 

 July and August 1939 by the San Francisco District, Corps of Engineers. (1939 and 1956). 



8. Bottom topography within Bolinas Lagoon was obtained from aerial photography 

 by R. M. Towill, Corp. for the Bolinas Harbor District, (Gilroy, 1970a), and by the USGS in 

 1967 from profiles of the bottom along 25 ranges. (Ritter, 1969.) 



9. Soundings in the Bolinas Lagoon entrance channel were made in October 1956 by 

 the San Francisco District, Corps of Engineers (1956). 



10. Three cross sections at the throat of the Bolinas Lagoon inlet were obtained when 

 the USGS measured the quantity of sediment moving in and out of the inlet, 22 June, 24-25 

 October 1967, and 16-17 May 1968. (Ritter, 1969.) 



2. Wave Data. The most important factors in coastal sediment processes in the nearshore 

 area are wave action and tidal currents. Wave data representative of the general area of 

 Bolinas Bay have been compiled from visual observations, the hindcasting technique, and a 

 recording wave meter. The nature and period of record of these various data follow: 



a. San Francisco Light Ship. These data were obtained by visual observation every 6 

 hours (0430, 1030, 1630, and 2230 PST) and transmitted to the U.S. Weather Bureau in 

 San Francisco where the wave height, period, and direction were entered in code on the 

 weather charts issued for each of these 6-hour periods. The weather charts for the 3-year 

 period from 1 September 1949 through 31 August 1952 were procured, and the wave data 

 summarized by wave roses. (Johnson, 1953.) These roses show the percent of time that 

 various wave heights and periods occurred during the various months of the year averaged 

 from the 3 years of record. Such data are relatively crude compared with the other data 

 listed below. 



b. Hindcast for Deepwater Station (37.5°N, 123.0°W). Wave roses were prepared for a 

 deepwater station by hindcasting from weather maps for the 3-year period 1936—1938. 

 (Scripps Institution of Oceanography, 1947.) The 3-year period was considered to give a 

 good representation of the average wave conditions, but did not necessarily include the most 

 extreme conditions which could occur. Data on southern swell also were not included. The 

 roses show the percent of time that waves of various heights occur during three periods 

 throughout the year— summer, winter, and a transition period. 



c. Hindcast for Deepwater Station (37.6°N, 123.5° W). Deepwater wave statistics for 10 

 stations along the California, Oregon, and Washington coasts were compiled by hindcasting 

 techniques using meteorological records and charts for the years 1956, 1957, and 1958. 

 (National Marine Consultants, 1960a, 1961.) The statistics include wave height, wave 

 direction, and wave period of both sea and swell, and are presented as monthly and annual 

 averages in both tabular form and roses. As in item b above, data on southern swell are not 

 included. Station 3 for the California coast (National Marine Consultants, 1960a) located at 

 Lat. 37.6°N and Long. 123. 5°W provides wave data which are representative of conditions 

 offshore from Bolinas Bay. 



