46 The Sea 
tent. Long Island Sound is a good example. The Tide Tables 
(issued by the U.S. Coast and Geodetic Survey, Washington, 
D.C.) indicate larger tides the further one penetrates into the 
Sound. To illustrate the point we have selected several points 
along the shore of the Sound, and listed the height of morn- 
ing high water on January Ist, 1944. 
New London, Conn. +9,4 ft. 
-Madison, Conn. +4.9 ft. 
Bridgeport, Conn. +6.8 ft. 
Willets Pt., N.Y. +7.4 ft. 
It will be noticed that the further from the mouth of the 
Sound, the greater the high water. 
HOW YOU MAY PREDICT THE TIDES 7 
An approximate way to estimate the time of high water at 
any particular port will now be described. 
Evidently, from what has already been said, the time of 
high water depends upon the time when the moon is in upper 
transit (that is, when it is highest in the sky). It is not neces- 
sary to watch the moon to see when it is highest in the sky. 
Its phase gives a good hint as to when that will occur. 
From the phase of the moon obtain the time of transit 
(take an intermediate value for in-between phases). Now 
add to this time the establishment of the port and the sum is 
the time of next high water. Another high water follows 
about 12 hours and 25 minutes later. The establishment of 
the port is a fixed quantity different for every port. It may 
be found in old editions of Nathaniel Bowditch’s American 
Practical Navigator (Hydrographic Office) or in the Tide 
Tables. 
