U = horizontal seepage velocity 



U = average horizontal velocity component 



U = horizontal velocity component at the free surface 



w = complex vertical velocity component 



W = vertical velocity component 



W, = vertical velocity component at the bottom 



W = vertical seepage velocity 



W = vertical velocity component at the free surface 



X = horizontal coordinate 



y = parameter defined by equation (103) 



z = vertical coordinate 



a. = laminar resistance coefficient 



a = constant associated with empirical formula for a 



3 = turbulent resistance coefficient 



6 = constant associated with empirical formula for S 

 o ^ 



6 = hydrodynamic characteristic of reference material 



3 = angle of impermeable slope 



6 = arbitrary phase angle 



£ = parameter as defined by equation (18) 



C = complex free surface elevation 



C = maximum free surface elevation in front of breakwater 

 ' ' 



jCpl = maximum free surface elevation behind breakwater 



n = time-dependent free surface elevation 



K = added mass coefficient 



A = parameter as defined by equation (34) 



