47 CFR § 80.335 - Procedures for canceling false distress alerts.
If a distress alert is inadvertently transmitted, the following steps shall be taken to cancel the distress alert.
(a) VHF Digital Selective Calling.
(1) Reset the equipment immediately;
(2) Immediately cancel the distress alert orally over the telephony distress traffic channel associated with each DSC channel on which the distress alert was transmitted;
(3) Set to Channel 16; and
(4) Transmit a broadcast message to “All stations” giving the ship's name, call sign or registration number, and MMSI, and cancel the false distress alert.
(b) MF Digital Selective Calling.
(1) Reset the equipment immediately;
(2) Immediately cancel the distress alert orally over the telephony distress traffic channel associated with each DSC channel on which the distress alert was transmitted; and
(3) Tune for radiotelephony transmission on 2182 kHz; and
(4) Transmit a broadcast message to “All stations” giving the ship's name, call sign or registration number, and MMSI, and cancel the false distress alert.
(c) HF Digital Selective Calling;
(1) Reset the equipment immediately;
(2) Immediately cancel the distress alert orally over the telephony distress traffic channel associated with each DSC channel on which the distress alert was transmitted;
(3) Tune for radiotelephony on the distress and safety frequency in each band in which a false distress alert was transmitted; and
(4) Transmit a broadcast message to “All stations” giving the ship's name, call sign or registration number, and MMSI, and cancel the false distress alert frequency in each band in which a false distress alert was transmitted.
(d) INMARSAT ship earth station. Immediately notify the appropriate rescue coordination center that the alert is cancelled by sending a distress priority message by way of the same land earth station through which the false distress alert was sent. Provide ship name, call sign or registration number, and INMARSAT identity with the cancelled alert message.
(e) EPIRB. If for any reason an EPIRB is activated inadvertently, immediately contact the nearest U.S. Coast Guard unit or appropriate rescue coordination center by telephone, radio or ship earth station and cancel the distress alert.
(f) General and other distress alerting systems. Notwithstanding paragraphs (a) through (e) of this section, ships may use additional appropriate means available to them to inform the nearest appropriate U.S. Coast Guard rescue coordination center that a false distress alert has been transmitted and should be cancelled.