Section 80.880 - Vessel radio equipment(a) Vessels operated solely within twenty nautical miles of shore must be equipped with a VHF radiotelephone installation as described in this subpart, and maintain a continuous watch on Channel 16.(b) Vessels operated solely within one hundred nautical miles of shore must be equipped with a medium frequency transmitter capable of transmitting J3E emission and a receiver capable of reception of J3E emission within the band 1710 to 2850 kHz, in addition to the VHF radiotelephone installation required by paragraph (a) of this section, and must maintain a continuous watch on 2182 kHz. Additionally, such vessels must be equipped with either: (1) A single sideband radiotelephone capable of operating on all distress and safety frequencies in the medium frequency and high frequency bands listed in § 80.369(a) and (b) , on all the ship-to-shore calling frequencies in the high frequency bands listed in § 80.369(d) , and on at least four of the automated mutual-assistance vessel rescue (AMVER) system HF duplex channels (this requirement may be met by the addition of such frequencies to the radiotelephone installation required by paragraph (b) of this section); or(2) If operated in an area within the coverage of an INMARSAT maritime mobile geostationary satellite in which continuous alerting is available, an INMARSAT ship earth station meeting the equipment authorization rules of parts 2 and 80 of this chapter. 68 FR 46973 , Aug. 7, 2003