allows the "correct" wave height value, H, to be determined from the uncor- 

 rected height, H., by using the simple equation 



H = (R H ) H 



(12) 



Contours of R,, are shown in Figure 3. The F and ft axes are the same as 

 in Figure 2. The boundary of the forbidden region is again indicated by the 

 curve labeled F = FM. Figure 3 shows that R u is always greater than 1.0 

 for F less than zero (for "adverse" currents where waves propagate against 

 the current) and R,, is less than 1.0 for F greater than zero (for "follow- 

 ing" currents where waves propagate with the current). Figure 3 also shows 

 that for a given value of F, adverse currents have a larger effect (i.e., 



R. 



values further removed from 1.0) than following currents. 



2.1 

 2.0 

 1.9 

 1.8 

 1.7 

 1.6 

 1.5 



T^ 1.4 

 £ 1.3 



'■o 1.2 



1.0 

 9 

 0.8 

 0.7 

 0.6 

 0.5 

 0.4 

 0.3 

 0.2 

 0.1 



1 1 1 1 1 r 



FORBIDDEN 

 REGION 



1.0 -0.8 



F [f= (Vcos0)/(q d T )" 2 ] 



Figure 3. Contours of dimensionless wave height factor, 

 Ru, given by equation (11). Waves cannot prop- 

 agate for values of F and Q which lie in the 

 forbidden region (boundary line F = FM). 



15 



