Written by Chuck Baier
March 22, 2021

The aids to navigation depicted on charts comprise a system of fixed and floating aids to navigation with varying degrees of reliability. Prudent mariners will not rely solely on any single aid to navigation, particularly a floating aid to navigation. With respect to buoys, the buoy symbol is used to indicate the approximate position of the buoy body and the sinker which secures the buoy to the seabed. The approximate position is used because of the practical limitations in positioning and maintaining buoys and their sinkers in precise geographical locations. These limitations include but are not limited to, inherent imprecision in position fixing methods, prevailing atmospheric and sea conditions, the slope of and the material making up the seabed, the fact that buoys are moored to sinkers by varying length of chain, and the fact that the buoy body and/or sinker positions are not under continuous surveillance, but are normally checked only during periodic maintenance visits which often occur more than a year apart. Due to the forces of nature, the position of the buoy body can be expected to shift inside and outside the charted symbol. The mariner is also cautioned that buoys may be extinguished or sound signals may not function as the result of ice, running ice, or other natural causes, collisions, or other accidents. For the foregoing reasons, a prudent mariner must not rely completely upon the position or operation of floating aids to navigation, but will also utilize bearings from fixed objects and aids to navigation onshore. Further, a vessel attempting to pass close aboard always risks collision with a yawing buoy or with the obstruction that the buoy marks.

Chuck Baier

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