Regulation 13 Provision and else of radios
This regulation applies to—
a vessel, other than a dumb craft, of 50 tons gross tonnage or more carrying explosives;
a vessel towing one or more dumb craft where the combined gross tonnage of all the dumb craft being towed is 50 tons or more and at least one is carrying explosives.
The master of a vessel to which this regulation applies shall ensure that, when it is in a harbour or harbour area, it is provided at all times with a radio capable of receiving and transmitting in the very high frequency band.
The master of a vessel to which this regulation applies shall ensure that a listening watch is kept on the operational frequency of the harbour authority at all times except—
when the vessel is at a berth; or
for short periods when the radio is tuned to another frequency for operational purposes.