should be nearly equal to T . 



The total nmnber of cases for c.;mputin[: the Ao versus "t" curves 

 is not equal to the total niunbGr of cases for computing the period. T ) 

 curves. The number of wave maxima are used in the fij^st, and the number 

 of waves are used in the latter. However, the Ap versus "V curves can 

 be drawn as a percentage of either the number of wave maxima or the number 

 of waves, since the ratio of the two is presumably known. This ratio for 

 a given depth can be determined from figure 9o 



The A.p curve is obtained from the ogive curve representing the dis- 

 tribution of waves with respect to period, and in fact iS' equal to 



fer^ eeY^'l^ p-r- wa\/ea oj\^V\ pertod ^ T uoWre 



\ rSjt" and Kr is the ratio of the number of W8,ve maxima to the number 

 of waves. The curves for Ap Ap etc., can not be deduced at this 



time, as there is no apparent relationship between a discrete amplitude 

 and a half -period distribution. 



E. REMARIS 



It has been established that some of the characteristics of bottom 

 pressures can be predicted. However, these forecasting techniques are 

 based on several basic assumptions which must be considered in any ap- 

 plication of the principles. The first assumption is that the sea surface 

 spectrum is known, either predicted from mnd conditions or measured. 

 Secondly, it has been considsred that the bottom is rigid and that there 

 will be no correction necessaiy to the basic attenuation factor 



28 



