47 CFR §80.207

1. (a)Authorization to use radiotelephone and radiotelegraph emissions by ship and coast stations includes the use of digital selective calling and selective calling techniques in accordance with § 80.225.
2. (b)In radiotelegraphy communications employing a modulated carrier the carrier must be keyed and modulated by an audio frequency.
3. (c)Authorization to use single sideband emission is limited to emitting a carrier;
   1. (1)For full carrier transmitters at a power level between 3 and 6 dB below peak envelope power;
   2. (2)For suppressed carrier transmitters at a power level at least 40 dB below peak envelope power; and
   3. (3)For reduced or variable level carrier:
      1. (i)In the 1600-4000 kHz band:
         1. (A)For coast station transmitters 18±2 dB below peak envelope power;
         2. (B)For ship station transmitters installed before January 2, 1982, 16±2 dB below peak envelope power; and
         3. (C)For ship station transmitters installed after January 1, 1982, 18±2 dB below peak envelope power.
      2. (ii)In the 4000-27500 kHz band:
         1. (A)For coast station transmitters 18±2 dB below peak envelope power;
         2. (B)For ship station transmitters installed before January 2, 1978, 16±2 dB below peak envelope power; and
         3. (C)For ship station transmitters installed after January 1, 1978, 18±2 dB below peak envelope power.
4. (d)The authorized classes of emission are as follows: