The physical oceanographic parameters that will be required from a 

 detail survey will generally include those properties which affect corrosion 

 of materials and the stability of the structure. For corrosion, the physical 

 and chemical properties indicated earlier will have to be evaluated. The 

 laboratory procedures to measure these properties are well established. A 

 few in-situ measuring instruments, however, are currently on the market 

 that will accurately and rapidly measure some of the required properties. 

 In particular, the salinity, temperature, and depth (STD) probe has proven 

 to be superior to conventional methods because of the capability of obtaining 

 continuous profiles of the water column. The initial cost of such probes is 

 high, but this investment is quickly recovered as illustrated in Figure 13, 

 which shows the results of the cost comparison study which was made for 

 the classical water bottle technique used by NCEL as compared to the in-situ 

 probe technique. Other techniques are indicated in the next section. 



8 20 













y 

 y 



s 











i 





y 

 y 



y 











y 



y 

 y 



STD 



probe 











y 















y 



y 

 y 

 y 



y 













* 

















30 40 



Number of Stations 



Figure 13. Comparison of sampling costs for classical water bottle method 

 and in-situ STD probe for stations with 3,000-foot water depths. 



25 



