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MANUAL OF MARINE METEOROLOGICAL OBSERVATIONS 



CODE TABLE 17 



Symbol P^ — Period oj waves 



Code 

 figures 



Period 



5 seconds or less. 



6 to 7 seconds. 

 8 to seconds. 

 10 to 11 seconds. 

 12 to 13 second.s. 

 14 to 15 seconds. 

 16 to 17 .seconds. 

 18 to 19 seconds. 

 20 to 21 seconds. 

 Over 21 seconds. 



Calm or period unable to be determined. 



CODE TABLE 18 



Symbol H,. — Height of waves 



Notes 



1. Each code figure except "zero" covers a range of 

 ^ meter; e. g., code figure 1 = % meter to ^ meter, code 

 figure 2 = % meter to \y^ meters. 



2. If the wave height is exactly between the heights 

 corresponding to two code figures, the lower code fig- 

 ure is reported. 



3. For wave heights greater than 31 feet (9^ meters), 

 the code figure for 30'/2 feet (9H meters) is reported 

 followed by the word "W.WKS" and the actual height 

 of the waves in feet or meters; e. g., "WAVES 37." 



