Sec. 80.877  Controls and indicators required for VHF radiotelephone 
          installation.

    The controls and indicators used on equipment of the VHF 
radiotelephone installation must meet the following standards:
    (a) The size of controls must easily permit normal adjustment. The 
function and the setting of the controls must be clearly indicated.d
    (b) Controls must be illuminated to permit satisfactory operation of 
the equipment.
    (c) Means must be provided to reduce to extinction any light output 
from the equipment which could affect safety of navigation.
    (d) An on/off switch must be provided for the entire installation 
with a visual indication that the installation is switched on.
    (e) The equipment must indicate the channel number, as given in the 
Radio Regulations, to which it is tuned. It must allow the determination 
of the channel number under all conditions of external lighting. Channel 
16 must be distinctively marked.
    (f) The receiver must have a manual volume control and a squelch 
control.
    (g) If the external controls are on a separate control unit and more 
than one such control unit is provided, the one on the bridge must have 
priority over the others. When there is more than one control unit, 
indication must be given to the other(s) that the transmitter is in 
operation.