

1 









1939- 1943 





- 











1934- 1943 













Total Observations = 528 

 Sampling Period = 2 years 



^ = 3.75 ft 

 C7,2= 11.77 ft2 









Total Observations = 5358 

 Sampling Period = 7 years 



^ = 3.99 ft 

 a2= 20.06 ft2 











-, 















































































- 

































































































5 10 15 20 25 30 35 40 



Significont Wove Height, ft 











1901- 1943 



Total Observations = 18,627 

 Sampling Period = 40 years 



^= 4.71ft 

 a^= 28.45 ft2 













Figure 2 - Combined Frequency Distributions 



of Significant Wave Heights Observed at 

 Ocean Station "Charlie" by Merchant Ships 



These Data were obtained from the U.S. Hydrographic 

 Office. X is the mean and a is the variance. 

























































































10 15 20 25 30 

 Significant Wave Height, ft 



35 40 



at that particular geographic location. It should be noted that the waves were of very small 

 height (less than llOcm = 4.6 ft). 



OBSERVED WAVE HEIGHTS AND MEASURED SHIP MOTIONS 



As pointed out in the introduction of this report, wave-height distributions could 

 reasonably be expected to have the same type of pattern as ship motions and stresses. This 

 similarity was evidenced by the weather ship USCGC CASCO.^ Figure 4 shows the frequency 

 distributions of wave-height observations and pitch-angle measurements made during this 

 test. Both were made at 3-hr intervals over a period of one month at station "Charlie." No 

 waves less than 1 ft nor pitch angles less than 1 deg were recorded. 



