Sec.  80.310   Watch required by voluntary vessels.

   Voluntary vessels not equipped with DSC must maintain a watch on 156.800 MHz
   (Channel 16) whenever the vessel is underway and the radio is not being used
   to communicate. Noncommercial vessels, such as recreational boats, may
   alternatively maintain a watch on 156.450 MHz (Channel 9) for call and reply
   purposes. Voluntary vessels equipped with VHF-DSC equipment must maintain a
   watch on either 156.525 MHz (Channel 70) or VHF Channel 16 aurally whenever
   the vessel is underway and the radio is not being used to communicate.
   Voluntary vessels equipped with MF-HF DSC equipment must have the radio
   turned on and set to an appropriate DSC distress calling channel or one of
   the radiotelephone distress channels whenever the vessel is underway and the
   radio is not being used to communicate. Voluntary vessels equipped with
   Inmarsat A, B, or C systems must have the unit turned on and set to receive
   calls whenever the vessel is underway and the radio is not being used to
   communicate.

   [ 68 FR 46967 , Aug. 7, 2003]

Distress, Alarm, Urgency and Safety Procedures