(3) Spring range: 1.49 m 



(4) Highest observed water levels: 



(a) Average yearly highest: 0.91 m above MHW 



(b) Highest observed: 1.65 m above MHW (6 March 1962) 



(5) Lowest observed water levels: 



(a) Average yearly lowest: 0.76 m below MLW 



(b) Lowest observed: 0.91 m below MLW (28 March 1955) 



3.0 



1.5 



> 



o 



m 

 < 



z 

 o 



< 

 > 



-1.5 



-3.0 



2.90 T 



-- 



DATUM OF BRETSCHNEIDER 

 ETAL.(1959): -0.76 

 -0.24m _o.91 ■ 



HIGHEST OBSERVED WATER LEVEL 

 (6 MARCH 1962) 



2.16 -- AVERAGE YEARLY HIGHEST 



1.25 -- MEAN HIGH WATER 



0.62 -- MEAN SEA LEVEL 



MEAN LOW WATER 



(NOS CHART DATUM) 



AVERAGE YEARLY LOWEST 

 LOWEST OBSERVED WATER LEVEL 

 (28 MARCH 1955) 



d. Predicted Astronomical Tides . The probabilities that the water will 

 be above a given level at any time are tabulated for Lewes, Delaware, in 

 Harris (1981), page 164. 



The lower limit (LL) of the hour by values are normalized with 

 respect to half the mean range (2.061 ft or 0.628 m) . In order to tabulate 

 the elevation above MLW with the corresponding probabilities (see Table 8-1), 

 the following calculation must be done: 



2.061 (1 + LL) = MLW elevation (ft) 



0.628 (1 + LL) = MLW elevation (m) 



8-10 



