Falttnsen 
(a) #y + fy out ¥%. “a qelepdheuitadsaeae 
ay Oz 
(b) -vy + $y = 0 on z = O outside the ship, 
dy 
(c) = 0 on the submerged part of the body, 
a6 5 
(d) condition to satisfy as y| — co 
For a definition of coordinates see Figure l. Further w is 
the frequency of encounter, t is the time variable, v is the wave 
number, nz2p is a two-dimensional normal to the body in the cross- 
sectional plane. 
Condition (d) is obtained by the matching procedure and it 
will be different for the zero-speed and the forward-speed problem. 
It should be noted that the longitudinal coordinate x will be a para- 
meter in the solution of yp. 
Ursell (1968 a and b) set upa similar equation system as 
above. The very important difference is the condition (d). His mathe- 
matical solution to (a), (b) and (c) did not agree with his condition 
(d). But it will agree with our condition (d). 
The solution to (a), (b), (c) and (d) can be written as 
or 
