§ 80.314 47 CFR Ch. I (10–1–00 Edition)
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; frequencies are indicated by footnote 2 (5) The kind of assistance desired; in § 80.361(b). (6) Any other information which might facilitate rescue. Frequency band Emission Carrier frequency (b) The radiotelephone distress mes- 405±535 kHz ...... A2B ...... 500 kHz. sage consists of: 1605±3500 kHz ...... J3E ...... 2182 kHz. (1) The distress signal MAYDAY; 4000±27, 5000 kHz .... A2B ...... 8364 kHz. 118±136 MHz ...... A3E ...... 121.500 MHz. (2) The name of the mobile station in 156±162 MHz ...... F3E, PON 156.800 MHz 156.750 distress; MHz. (3) Particulars of its position; 243 MHz ...... A3N ...... 243.000 MHz. (4) The nature of the distress; (5) The kind of assistance desired; The maximum transmitter power ob- (6) Any other information which tainable may be used. might facilitate rescue, for example, [51 FR 31213, Sept. 2, 1986; 51 FR 34984, Oct. 1, the length, color, and type of vessel, 1986] number of persons on board. (c) As a general rule, a ship must sig- § 80.314 Distress signals. nal its position in latitude and lon- (a) The international radiotelegraphy gitude, using figures for the degrees distress signal consists of the group and minutes, together with one of the ‘‘three dots, three dashes, three dots’’ words NORTH or SOUTH and one of the (... ---...), symbolized herein by SOS, words EAST or WEST. In radio- transmitted as a single signal in which telegraphy, the signal .-.-.- must be the dashes are slightly prolonged so as used to separate the degrees from the to be distinguished clearly from the minutes. When practicable, the true dots. bearing and distance in nautical miles (b) The international radiotelephone from a known geographical position distress signal consists of the word may be given. MAYDAY, pronounced as the French expression ‘‘m’aider’’. § 80.317 Radiotelegraph and radio- (c) These distress signals indicate telephone alarm signals. that a mobile station is threatened by (a) The international radiotelegraph grave and imminent danger and re- alarm signal consists of a series of quests immediate assistance. twelve dashes sent in one minute, the duration of each dash being four sec- § 80.315 Distress calls. onds and the duration of the interval (a) The radiotelegraph distress call between consecutive dashes one second. consists of: The purpose of this special signal is the (1) The distress signal SOS, sent actuation of automatic devices giving three times; the alarm to attract the attention of (2) The word DE; the operator when there is no listening (3) The call sign of the mobile station watch on the distress frequency. in distress, sent three times. (b) The international radiotelephone (b) The radiotelephone distress call alarm signal consists of two substan- consists of: tially sinusoidal audio frequency tones (1) The distress signal MAYDAY spo- transmitted alternately. One tone ken three times; must have a frequency of 2200 Hertz (2) The words THIS IS; and the other a frequency of 1300 Hertz, (3) The call sign (or name, if no call the duration of each tone being 250 mil- sign assigned) of the mobile station in liseconds. When generated by auto- distress, spoken three times. matic means, the radiotelephone alarm signal must be transmitted continu- § 80.316 Distress messages. ously for a period of at least 30 seconds, (a) The radiotelegraph distress mes- but not exceeding one minute; when sage consists of: generated by other means, the signal (1) The distress signal SOS; must be transmitted as continuously
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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 ate automatic devices giving the answer is received. The radiotelegraph alarm. alarm signal may also be repeated, if necessary. § 80.318 Use of alarm signals. (d) The transmissions under para- (a) The radiotelegraph or radio- graphs (a) (5) and (6) of this section, telephone alarm signal, as appropriate, which are to permit direction finding must only be used to announce: stations to determine the position of (1) That a distress call or message is the station in distress, may be repeated about to follow; at frequent intervals if necessary. (2) The transmission of an urgent cy- (e) When the mobile station in dis- clone warning. In this case the alarm signal may only be used by coast sta- tress receives no answer to a distress tions authorized by the Commission to message transmitted on the distress do so; or frequency, the message may be re- (3) The loss of a person or persons peated on any other available fre- overboard. In this case the alarm sig- quency on which attention might be nal may only be used when the assist- attracted. ance of other ships is required and can- not be satisfactorily obtained by the § 80.320 Radiotelephone distress call use of the urgency signal only, but the and message transmission proce- alarm signal must not be repeated by dure. other stations. The message must be (a) The radiotelephone distress proce- preceded by the urgency signal. dure consists of: (b) In cases described in paragraphs (1) The radiotelephone alarm signal (a)(2) and (3) of this section, the trans- (whenever possible); mission of the warning or message by (2) The distress call; radiotelegraphy must not begin until (3) The distress message. two minutes after the end of the radio- (b) Radiotelephone distress trans- telegraph alarm signal. missions must be made slowly and dis- § 80.319 Radiotelegraph distress call tinctly, each word being clearly pro- and message transmission proce- nounced to facilitate transcription. dure. (c) After the transmission by (a) The radiotelegraph distress proce- radiotelephony of its distress message, dure consists of the following six steps: the mobile station may be requested to however, when time is vital, the first transmit suitable signals followed by and second steps may be omitted. its call sign or name, to permit direc- These two steps of the distress proce- tion-finding stations to determine its dure may also be omitted in cir- position. This request may be repeated cumstances when transmission of the at frequent intervals if necessary. alarm signal is considered unnecessary: (d) The distress message, preceded by (1) The radiotelegraph alarm signal; the distress call, must be repeated at (2) The distress call and an interval intervals until an answer is received. of two minutes; This repetition must be preceded by (3) The distress call; the radiotelephone alarm signal when- (4) The distress message; ever possible. (5) Two dashes of ten to fifteen sec- (e) When the mobile station in dis- onds each; tress receives no answer to a distress (6) The call sign of the mobile station message transmitted on the distress in distress. (b) The radiotelegraph distress trans- frequency, the message may be re- missions must be sent by means of the peated on any other available fre- international Morse code at a speed not quency on which attention might be exceeding 16 words per minute nor less attracted. than 8 words per minute.
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