Chryssostomtdts 
fore in designs where previous experience has demonstrated that sea- 
keeping performance is satisfactory seakeeping experiments should be 
omitted. However where no previous experience is available, as in 
the case of a novel design, such experiments are highly recommended. 
IV - CONCLUSIONS 
From the results presented in the previous sections the author 
has concluded that it is advantageous to incorporate seakeeping consi- 
derations in preliminary ship design optimization programs because 
of the potential payoff. However seakeeping considerations should 
only be included where it is meaningful to do so for example when the 
speed and size of ships are variable. They should not be included when 
only small changes in the principal characteristics of the ship are 
contemplated as they will not affect the final outcome. 
Special attention was drawn to the case of novel designs where 
seakeeping can be the controlling factor in the feasibility of the system. 
In this case seakeeping must be considered at the outset of the study. 
Although the state of the art permits the incorporation of 
seakeeping considerations in the design of monohulls improvement in 
the theory in certain areas will be worthwile as it will permit a better 
analysis. In particular, improvementin the theory to permit better 
predictions for added resistance, propulsive efficiency and viscous 
roll damping is considered worthwhile. In addition a better definition 
of the motion indices is necessary. 
NOMENCLATURE 
B beam 
CB block coefficient 
EHP effective horse power 
Fn Froude number 
g acceleration of gravity 
Hl/3 significant wave height 
J advance coefficient 
K, thrust coefficient 
1612 
