[Code of Federal Regulations]

[Title 33, Volume 1]

[Revised as of July 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 33CFR62.47]



[Page 150-151]

 

                TITLE 33--NAVIGATION AND NAVIGABLE WATERS

 

         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY

 

PART 62_UNITED STATES AIDS TO NAVIGATION SYSTEM--Table of Contents

 

              Subpart B_The U.S. Aids to Navigation System

 

Sec. 62.47  Sound signals.



    (a) Often sound signals are located on or adjacent to aids to 

navigation. When visual signals are obscured, sound signals warn 

mariners of the proximity of danger.

    (1) Sound signals are distinguished by their tone and phase 

characteristics.

    (i) Tones are determined by the devices producing the sound (i.e., 

diaphones, diaphragm horns, reed horns, sirens, whistles, bells and 

gongs).



[[Page 151]]



    (ii) Phase characteristics are defined by the signal's sound 

pattern, i.e., the number of blasts and silent periods per minute and 

their durations. Sound signals emanating from fixed structures generally 

produce a specific number of blasts and silent periods each minute when 

operating. Buoy sound signals are generally actuated by the motion of 

the sea and therefore do not emit a regular signal characteristic.

    (2) Where no live watch is maintained, sound signals are normally 

operated continuously. However, some are equipped with fog detectors 

which activate sound signals when visibility falls below a predetermined 

limit.

    (b) Mariners should not rely solely on sound signals to determine 

their positions for the following reasons:

    (1) Distance cannot be accurately determined by sound intensity.

    (2) Occasionally sound signals may not be heard in areas close to 

their location.

    (3) Signals may not sound in cases where fog exists close to, but 

not at, the location of the sound signal.

    (4) As buoy signals are generally activated by sea motion, they may 

produce no signals when seas are calm.

    (5) As previously noted, buoy positions are not always reliable. 

Therefore their sound signals cannot be assumed to be emanating from a 

fixed position.