102 U. S. COAST AND GEODETIC SURVEY 
And like the variations in high water and in sea level, the annual variation in low water 
shows definite regional characteristics. 
Yearly Low Water 
Within a year the annual variation in low water is eliminated, and hence yearly 
values of low water differ much less than monthly values. Figure 48 shows the yearly 
heights of low water for the 25 year period 1924-1948 at Boston, Los Angeles and Pensa- 
cola. Generally, consecutive heights of yearly low water at each of these stations are 
seen to differ by not more than a few hundredths of a foot, but occasionally this differ- 
UZ) 1930 1935 1940 1945 
Boston 
Los Angeles 
Pensacola 
Fic. 48.—Yearly heights of low water, Boston, Los Angeles, and Pensacola, 1924-48. 
