[(e-H^)/*] 

 F(H ) = e-^ (C2) 



s 



3. At least two data points of transmitted wave height versus a return 

 period of the associated incident wave height are also required to transform 

 the incident probability distribution to an Extremal Type I cumulative proba- 

 bility distribution of transmitted waves F(H^) . The transformation is ac- 

 complished by a least squares fit of the Extremal Type I function above to the 

 H^ points, given the cumulative probability of the corresponding incident H 

 value as represented by the traditional return period. The nonlinear coeffi- 

 cient of correlation and sum of least squares are computed to indicate the 

 goodness of the fit. A table of residuals is optionally provided. 



4. The transmitted wave heights during any storm represented by H 



are probably not Rayleigh distributed, but the transmitted wave height associ- 

 ated with a given -incident significant wave height is assumed to be at the 

 13.5 percent exceedance level among all transmitted waves (including those of 

 zero height). This is the same exceedance level as the significant wave 

 height in a Rayleigh distributed sea state. The methods of Andrew and Smith 

 (in preparation) can be applied to estimate the transmitted wave heights at 

 other exceedance levels. 



5. The program BWL0SS2, in a manner similar to its sister program 

 BWL0SS1, computes an expected, or long-term, average annual economic loss due 

 to transmitted waves by the following formulation: 



H 



SCO 



E\f^] = X f $L(H^) 

 "lo 



dF(H^) 



dH. 

 t J 



"^"t (C3) 



where [dF(H^)/dH^] is the probability density function f(H^.) associated 

 with F(Hi.) . X is the Poisson parameter, or average number of extreme 

 events per year, as defined to derive F(H ) . The assumption of a random 

 number of extreme events per year which can be represented by a mean value in- 

 dependent of individual H (or H^^) values, is critical to the above defini- 

 tion of E{$L'/yr} . $L(H ) is taken to describe also $L(H^.) since the 

 transmitted waves are now the incident waves to the facilities and operations 

 incurring losses. H^. thus represents the intensity of the transmitted wave 



C2 



