47 CFR 80.367 - General uses
(a) Ship stations communicating with foreign coast stations may operate on any frequency designated by that coast station.
(b) Radiotelephony stations communicating with a Government station may transmit on a Government frequency when authorized to do so by the Government station or agency if the emission, bandwidth and frequency tolerance of the maritime station are within the same limits as the Government station.
(c) Frequencies assigned to Government radio stations are assignable to non-Government maritime stations for radiotelephony communications with other non-Government stations in connection with activities performed in coordination with or on behalf of the Government.
(d) Frequencies in the 2000-27500 kHz band will be authorized only to ship stations that in addition are authorized to use frequencies in the 156-162 MHz band.
(e) Frequencies in the 2000-2850 kHz band will be authorized to private coast stations that in addition are authorized to use frequencies in the 156-162 MHz band.
(f) Ship and coast stations authorized to use frequencies in both the 2000-27500 kHz and 156-162 MHz bands must not use frequencies in the 2000-27500 kHz band for communications with any other station which is within the VHF service range.
(g) Coast and ship station radiotelephone working frequencies are available for DSC general purpose calling under the provisions of § 80.207(a).
(h) Digital selective calling techniques are not authorized on the frequencies 2182 kHz or 156.800 MHz.