descending order, and the highest M/ 3 values selected. The average 

 of the M/ 3 highest waves would then be the significant height. 



As an example, consider the series of recorded values given below 

 as they may have occurred in an observation: 



■J, -J, V'. 6, ^ y, 6, 8, ^, ^ 



y. 6, 6, 8. 10 12, 8, 6, 6, y 



y, 6, 6, 8, 8 10, 12, 14, 16, 12 



8, 6, 6, Vi V V. -v/. -«/. 6f 6 



6, 6, 8, 8, 10 8, 6, 6, J, -J 



■vA V. V. 6, 6 8, 6, 8, Vi v 



->/ y. V< ■/. y 6, 6, 8, 8, 10 



10, 10, 8, 6. 6 y. y. v^ 6, 6 



6, 6, 8, 8, 8 6, 8, 10, 8, 8 



6, v', V> v^ \/ 6, 6, »J, ^, ^ 



There is a total of 100 height observations. There are 37 check 

 values for low waves less than 6 feet high. There are 31 six-foot 

 w^aves, 20 eight-foot waves, and so on. 



The lowest two- thirds of the waves must be eliminated from the 

 computations, so the sixty- seven lowest waves must be left out. The 

 thirty- seven lowest waves automatically drop out, and then thirty 

 of the six-foot high waves are eliminated. Thus the one- third highest 

 waves consist of the values of the heights greater than six feet and 

 one six-foot wave to make up a total of 33. 



The average of the one- third highest waves is then computed according 

 to the following procedure: 



Height 



6 



8 

 10 

 12 

 14 

 16 

 TOTAL 



Significant height = 33= 9.2 feet 



20 



