in duration and width. The elemental unit of construction 
would be a finite wave group which would last for only a few 
minutes and be only a few kilometers wide as it passed the line 
x = 0 near a point’ y = Yor 
The most realistic model possible by these methods would 
be a model something like the last model described briefly in 
Chapter 6. The analysis of the properties of the model would 
turn out to be very complex, and the results would be indecisive 
because of the difficulties involved in evaluating the potential 
energy. 
None of the above possible models would be Gaussian in 
character, and since there is evidence that a wave record is 
very nearly Gaussian in character as shown in Chapter 7, they 
would all be unrealistic. For this reason, none of these models 
will be treated. 
Instead, in Chapter 9, the Gaussian case for a short crested 
sea surface will be treated, and FF(x,y,t) as derived in this 
chapter will be applied as a filter to the Gaussian case in 
order to forecast the spectrum of the waves in the area of 
decaye 
5 208. 
