Figure 3.--Track chart of cruise TO-59-2. 



PROCEDURES 



Observations were made on station and 

 between stations. 



Holmes and Blackburn (1960) distinguished 

 four kinds of station: regular forenoon, regular 

 night, in situ, and "special". The first three 

 kinds were occupied along a prearranged track 

 when the appropriate times of day, rather than 

 particular positions, were reached: this is 

 appropriate in situations where variation in 

 ocean properties between times of day can 

 be expected to be large compared with that 

 between days or areas; e.g., in surveys of 

 large and fairly uniform regions of the tropical 

 ocean, especially surveys in which emphasis is 

 placed upon distribution of biological prop- 

 erties. The other ("special") stations were 

 occupied according to position rather than 



time of day: this is appropriate in situations 

 where between-days and between-areas varia- 

 tion can be expected to be as large as variation 

 between times of day or larger, or where the 

 latter source of variation is of less interest, 

 so that the principal need is for a series of 

 stations to be occupied at prearranged places 

 in the shortest possible time; e.g., in surveys 

 of coastal regions where conditions are highly 

 variable in time and space, especially surveys 

 in which emphasis is placed upon distribution 

 of physical properties. 



The main purpose of these three cruises 

 was to make synoptic pattern-like surveys in 

 the Gulf of Tehuantepec, and a similar operation 

 in Baja California waters was carried out on 

 TO-59-2. The procedure on these surveys was 

 to work along the prearranged station pattern 

 as quickly as possible, making standard 



