47 CFR 80.1133 - Transmission of safety communications.
(a) In a terrestrial system the announcement of the safety message must be made on one or more of the distress and safety calling frequencies specified in § 80.1077 using digital selective calling techniques. A separate announcement need not be made if the message is to be transmitted through the maritime mobile-satellite service.
(b) The safety signal and message must normally be transmitted on one or more of the distress and safety traffic frequencies specified in § 80.1077, or via the maritime mobile satellite service or on other frequencies used for this purpose.
(c) The safety signal consists of the word SECURITE. In radiotelephony, it is pronounced as in French.
(d) The safety call format or the safety signal indicates that the calling station has an important navigational or meteorological warning to transmit.
(e) In radiotelephony, the safety message must be preceded by the safety signal, repeated three times, and the identification of the transmitting station.
(f) In narrow-band direct-printing, the safety message must be preceded by the safety signal and the identification of the transmitting station.
(g) Error correction techniques, in accordance with ITU-R M.625-3 (incorporated by reference, see § 80.7), as specified in § 80.1101, must be used for safety messages by direct-printing telegraphy. All messages must be preceded by at least one carriage return, a line feed signal, a letter shift signal, and the safety signal SECURITE.
(h) Safety communications by direct-printing telegraphy should be in the ARQ mode when communicating directly to the Coast Guard or other coast stations on channels which they normally guard. Other distress communications, including those on simplex channels provided for that purpose, should be in the broadcast forward error correction mode. The ARQ mode may subsequently be used when it is advantageous to do so.