EXPLANATION OF THE TABLE 
This table contains the distances, in nautical and statute miles, at which any 
object is visible at sea. It is calculated by the formula: 
d=1.157z, and d'=1.32/z, 
in which d is the distance in nautical miles, d’ the distance in statute miles, 
and zx the height of the eye or the object in feet. 
To find the distance of visibility of an object, the distance given by the table 
corresponding to its height should be added to the distance corresponding to 
the height of the observer’s eye. 
EXAMPLE: Required the distance of visibility of an object 420 feet high, the 
observer being at an elevation of 15 feet. 
Distance corresponding to 420 feet is 23.5 nautical miles. 
Distance corresponding to 15 feet is 4.4 nautical miles. 
Distance of visibility.______- 27.9 nautical miles. 
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