Table 4-10. Deepwater Wave Heights, in Percent by Direction, off East-Facing 

 Coast of Inland Sea 



*Calm conditions, or waves from SW, W, or NW. 



t Shipboard visual observations assumed equivalent to significant height 

 (See Walton, 1972.) 



This problem could be solved using Figure 4-39, but for illustration, 

 and because of a slightly higher degree of accuracy from the direction 

 data given, the problem is illustrated in detail. 



In this example, the available data are the joint frequency distri- 

 bution of H^ and a^. For each combination of a.^ and H^, the 



corresponding CL h is calculated for Table 4-11 in the following 



o ' o 

 manner. The basic equation is a form of Equation 4-40 written 



'% ' ^o 



- |f^^^Ja..H > 



(4-41) 



where f is the decimal frequency, which is the percent frequency in 

 Table 4-10, divided by 100. The constant. A, is of the type used in 

 Equation 4-40. 



Since the available data are a^ and H(p, the appropriate equation 

 for ViQ is given in Table 4-8. If A = 7.5 x 10^ as in Equation 4-40 

 and Equation 4-36 in Table 4-8 are used. 



where 



^%-Ho = 1-^73 X 10^ fH//^ F(,^| 



(4-42) 



(4-43) 



Tills direction term, f^(a^) , requires careful consideration. A 

 compass point direction for the given data (Table 4-10) represents a 45' 



4-105 



