USCG Exam PracticeTides and currents — predictions and corrections
A master of a towing vessel determines that no charted aids to navigation other than buoys are available to fix the vessel's position in a confined waterway. Under 33 CFR §164.78, which statement correctly describes the regulatory guidance regarding the use of buoys for position fixing?
- A. Buoys may be used as the sole means of fixing position at any time because they are official aids to navigation maintained by the Coast Guard
- B. Buoys may not be used for position fixing under any circumstances and the vessel must anchor until other means are available
- ✓ Buoys alone may not fix a position; they may corroborate a position fixed by other means, but if no other aids are available, buoys alone may establish only an estimated positionCorrect
- D. Buoys may fix a position provided the master verifies their charted positions against a current Light List before transiting
Why C is correct
33 CFR §164.78(a)(3) explicitly states that buoys are placed in approximate positions and may not maintain exact charted positions due to currents, seas, ice, and collisions. They may corroborate a position fixed by other means, but if no other aids are available, buoys alone may establish only an estimated position — not a fixed position.
Cited:33 CFR §164.78