Federal Communications Commission § 80.316 § 80.310 Watch required by voluntary frequencies are indicated by footnote 2 vessels. in § 80.361(b). Voluntary vessels not equipped with Frequency band Emission Carrier frequency DSC must maintain a watch on 156.800 MHz (channel 16) whenever the radio is 405–535 kHz .............. A2B .......... 500 kHz. 1605–3500 kHz .......... J3E .......... 2182 kHz. operating and is not being used to com- 4000–27, 5000 kHz .... A2B .......... 8364 kHz. municate. Noncommercial vessels, 118–136 MHz ............. A3E .......... 121.500 MHz. such as recreational boats, may alter- 156–162 MHz ............. F3E, PON 156.800 MHz 156.750 MHz. natively maintain a watch on 156.450 243 MHz ..................... A3N .......... 243.000 MHz. MHz (channel 9) for call and reply pur- poses. The maximum transmitter power ob- [57 FR 19552, May 7, 1992] tainable may be used. [51 FR 31213, Sept. 2, 1986; 51 FR 34984, Oct. 1, DISTRESS, ALARM, URGENCY AND 1986] SAFETY PROCEDURES § 80.314 Distress signals. § 80.311 Authority for distress trans- (a) The international radiotelegraphy mission. distress signal consists of the group A mobile station in distress may use ‘‘three dots, three dashes, three dots’’ any means at its disposal to attract at- (... ---...), symbolized herein by SOS, tention, make known its position, and transmitted as a single signal in which obtain help. A distress call and mes- the dashes are slightly prolonged so as sage, however, must be transmitted to be distinguished clearly from the only on the authority of the master or dots. person responsible for the mobile sta- (b) The international radiotelephone tion. No person shall knowingly trans- distress signal consists of the word mit, or cause to be transmitted, any MAYDAY, pronounced as the French false or fraudulent signal of distress or expression ‘‘m’aider’’. related communication. (c) These distress signals indicate that a mobile station is threatened by § 80.312 Priority of distress trans- grave and imminent danger and re- missions. quests immediate assistance. The distress call has absolute pri- ority over all other transmissions. All § 80.315 Distress calls. stations which hear it must imme- (a) The radiotelegraph distress call diately cease any transmission capable consists of: of interfering with the distress traffic (1) The distress signal SOS, sent and must continue to listen on the fre- three times; quency used for the emission of the dis- (2) The word DE; tress call. This call must not be ad- (3) The call sign of the mobile station dressed to a particular station. Ac- in distress, sent three times. knowledgement of receipt must not be (b) The radiotelephone distress call given before the distress message consists of: which follows it is sent. (1) The distress signal MAYDAY spo- ken three times; § 80.313 Frequencies for use in dis- (2) The words THIS IS; tress. (3) The call sign (or name, if no call The frequencies specified in the sign assigned) of the mobile station in bands below are for use by mobile sta- distress, spoken three times. tions in distress. The conventional emission is shown. When a ship station § 80.316 Distress messages. cannot transmit on the designated fre- (a) The radiotelegraph distress mes- quency or the conventional emission, it sage consists of: may use any available frequency or (1) The distress signal SOS; emission. Frequencies for distress and (2) The name of the mobile station in safety calling using digital selective distress; calling techniques are listed in (3) Particulars of its position; § 80.359(b). Distress and safety NB-DP (4) The nature of the distress; 73 VerDate 0ct<31>2002 10:08 Dec 13, 2002 Jkt 197192 PO 00000 Frm 00073 Fmt 8010 Sfmt 8010 Y:\SGML\197192T.XXX 197192T § 80.317 47 CFR Ch. I (10–1–02 Edition) (5) The kind of assistance desired; ate automatic devices giving the (6) Any other information which alarm. might facilitate rescue. (b) The radiotelephone distress mes- § 80.318 Use of alarm signals. sage consists of: (a) The radiotelegraph or radio- (1) The distress signal MAYDAY; telephone alarm signal, as appropriate, (2) The name of the mobile station in must only be used to announce: distress; (1) That a distress call or message is (3) Particulars of its position; about to follow; (4) The nature of the distress; (2) The transmission of an urgent cy- (5) The kind of assistance desired; clone warning. In this case the alarm (6) Any other information which signal may only be used by coast sta- might facilitate rescue, for example, tions authorized by the Commission to the length, color, and type of vessel, do so; or number of persons on board. (3) The loss of a person or persons (c) As a general rule, a ship must sig- overboard. In this case the alarm sig- nal its position in latitude and lon- nal may only be used when the assist- gitude, using figures for the degrees ance of other ships is required and can- and minutes, together with one of the not be satisfactorily obtained by the words NORTH or SOUTH and one of the use of the urgency signal only, but the words EAST or WEST. In radio- alarm signal must not be repeated by telegraphy, the signal .-.-.- must be other stations. The message must be used to separate the degrees from the preceded by the urgency signal. minutes. When practicable, the true (b) In cases described in paragraphs bearing and distance in nautical miles (a)(2) and (3) of this section, the trans- from a known geographical position mission of the warning or message by may be given. radiotelegraphy must not begin until two minutes after the end of the radio- § 80.317 Radiotelegraph and radio- telegraph alarm signal. telephone alarm signals. (a) The international radiotelegraph § 80.319 Radiotelegraph distress call alarm signal consists of a series of and message transmission proce- twelve dashes sent in one minute, the dure. duration of each dash being four sec- (a) The radiotelegraph distress proce- onds and the duration of the interval dure consists of the following six steps: between consecutive dashes one second. however, when time is vital, the first The purpose of this special signal is the and second steps may be omitted. actuation of automatic devices giving These two steps of the distress proce- the alarm to attract the attention of dure may also be omitted in cir- the operator when there is no listening cumstances when transmission of the watch on the distress frequency. alarm signal is considered unnecessary: (b) The international radiotelephone (1) The radiotelegraph alarm signal; alarm signal consists of two substan- (2) The distress call and an interval tially sinusoidal audio frequency tones of two minutes; transmitted alternately. One tone (3) The distress call; must have a frequency of 2200 Hertz (4) The distress message; and the other a frequency of 1300 Hertz, (5) Two dashes of ten to fifteen sec- the duration of each tone being 250 mil- onds each; liseconds. When generated by auto- (6) The call sign of the mobile station matic means, the radiotelephone alarm in distress. signal must be transmitted continu- (b) The radiotelegraph distress trans- ously for a period of at least 30 seconds, missions must be sent by means of the but not exceeding one minute; when international Morse code at a speed not generated by other means, the signal exceeding 16 words per minute nor less must be transmitted as continuously than 8 words per minute. as practicable over a period of approxi- (c) The distress message, preceded by mately one minute. The purpose of this the distress call, must be repeated at special signal is to attract the atten- intervals, especially during the 500 kHz tion of the person on watch or to actu- international silence periods, until an 74 VerDate 0ct<31>2002 10:08 Dec 13, 2002 Jkt 197192 PO 00000 Frm 00074 Fmt 8010 Sfmt 8010 Y:\SGML\197192T.XXX 197192T Federal Communications Commission § 80.323 answer is received. The radiotelegraph ceipt. However, in areas where reliable alarm signal may also be repeated, if communication with one or more coast necessary. stations is practicable, ship stations (d) The transmissions under para- may defer this acknowledgement for a graphs (a) (5) and (6) of this section, short interval so that a coast station which are to permit direction finding may acknowledge receipt. stations to determine the position of (b) Stations of the maritime mobile the station in distress, may be repeated service which receive a distress mes- at frequent intervals if necessary. sage from a mobile station which be- (e) When the mobile station in dis- yond any possible doubt is not in their tress receives no answer to a distress vicinity, must allow a short interval of message transmitted on the distress time to elapse before acknowledging frequency, the message may be re- receipt of the message in order to per- peated on any other available fre- mit stations nearer to the mobile sta- quency on which attention might be tion in distress to acknowledge receipt attracted. without interference. § 80.320 Radiotelephone distress call § 80.322 Form of acknowledgement. and message transmission proce- dure. (a) The acknowledgement of receipt of a radiotelegraph distress message is (a) The radiotelephone distress proce- transmitted in the following form: dure consists of: (1) The distress signal SOS; (1) The radiotelephone alarm signal (2) The call sign of the station send- (whenever possible); ing the distress message, sent three (2) The distress call; times; (3) The distress message. (3) The word DE; (b) Radiotelephone distress trans- (4) The call sign of the station ac- missions must be made slowly and dis- knowledging receipt, sent three times; tinctly, each word being clearly pro- (5) The group RRR; nounced to facilitate transcription.