Table 9 - Determination of Significant Design Wave Heights 





Direction 



Significant 

 Deep Water 

 Wave Height 



Perioci Range 



Refraction 

 Goefficient-"- 



Refracted 

 Wave Height 



(1) 



{2) 

 (feet) 



(3) 

 (seconds) 



{ 



(5) 

 (feet) 



W 



15 



8 

 10 

 12 



0.10 

 0.07 

 O.Oli 



1.5 

 1.0 



0.5 



im^ 



12 



8 

 10 

 12 



0.15 



0.12 

 0.09 



2.0 



1.5 



1.0 



w 



10 



10 

 12 

 2h 

 16 



0.30 

 0.31 

 0.20 

 0.25 



3.0 

 3,0 

 2.0 

 2.5 



WSI^ 



10 



10 

 12 

 Ih 

 16 



0.60 



0.50 

 0.35 

 0.35 



6,05Ht 



5.0 

 3S 



sw 



8 



12 



11; 

 16 



0,72 

 0.59 

 O.liO 



6.0K- 



5.0 

 3*0 



■54- This refraction coefficient is equal to y -r- (H/H'). 

 *-»■ Adopted as the significant design wave hei^t. 



Columns 1, 2, and 3 are taken from the statistical wave data as deter- 

 mined from sjmoptic weather charts . 



Column k is determined from the relative distances between two adj-cent 

 orthogonals in deep water and in shallow water 



Column 5 is the product of columns 2 and h 



198. In the preceding example, although the highest deep water waves 

 approached from directions ranging from W to NW, tlie refraction study in- 

 dicated that higher waves inshore may be expected from more southerly 

 directions. 



199* It must be remembered that the accuracy with which refraction 

 procedure may be applied in the determination of design wave characteristics 

 decreases as the underwater contours over which the refraction diagrams must 

 be drawn become more coiiplex. Under highly coirplex bottom conditions direct 

 observations may be required. 



100 



