An international distress frequency is a radio frequency that is designated for emergency communication by international agreement.

History

For much of the 20th century, 500 kHz was the primary international distress frequency. Its use has been phased out in favor of the Global Maritime Distress Safety System.

Use of some distress frequencies is permitted for calling other stations to establish contact, whereupon the stations move to another frequency. Such channels are known as distress, safety and calling frequencies.[1]

Satellite processing from all 121.5 or 243 MHz locators has been discontinued. Since February 1, 2009, the U.S. Coast Guard only monitors distress signals from emergency position indicating radio beacons (EPIRBs) that broadcast using digital 406 MHz signals.[2] Digital 406 MHz models became the only ones approved for use in both commercial and recreational watercraft worldwide on January 1, 2007.[3]

Maritime Mobile Service frequencies

International distress frequencies, currently in use are:

Digital selective calling frequencies

Several maritime frequencies are used for digital selective calling (DSC), and they are also monitored for DSC distress signals:[6][7]

Aeronautical frequencies

Search And Rescue frequencies

Amateur radio frequencies

VHF, UHF calling frequencies can also be used to make emergency calls

Band Global Region 1
Europe, Africa		 Region 2
The Americas[8]		 Region 3
Asia
13 cm
23 cm 1294.500 MHz (U.S.)
33 cm N/A 927.500 MHz (U.S.) N/A
70 cm 433.500 MHz (EU) 446.00 MHz (U.S.)
1.25 m N/A 223.500 MHz (U.S.) N/A
2 m 145.500 MHz (EU) 146.520 MHz (U.S. & Canada) 145.000 MHz (India, Indonesia & Thailand)
2 m 144.740 MHz Philippines [9]
4 m 70.450 MHz (EU) N/A
6 m 52.525 MHz
10 m 29.600 MHz
12 m RTTY/Packet only

MF and HF frequencies

Band Global[10][11] Region 1[12]
Europe, Africa		 Region 2[13]
The Americas		 Region 3[14]
Asia
15 m 21360 kHz
17 m 18160 kHz
20 m 14300 kHz
30 m
40 m n/a 7110 kHz 7060 kHz

7240 kHz 7275 kHz

7110 kHz
60 m n/a
80 m n/a 3760 kHz 3750 kHz

3985 kHz

3600 kHz

Other frequencies

See also

References

  1. ^ Bartlett, Tim (2006). VHF Handbook. Southampton: The Royal Yachting Association. pp. 28, 31. ISBN 978-1-905104-03-1.
  2. ^ "Logon Form". www.piersystem.com.
  3. ^ "Logon Form". www.piersystem.com.
  4. ^ "USCG: Commercial Fishing Vessel Safety Program - 13th Coast Guard District - Guardians of the Pacific Northwest". www.uscg.mil.
  5. ^ UK Hydrographic Office (2017). Volume 1 (NP281) - Maritime Radio Stations (Parts 1 & 2). UK: UK Hydrographic Office.
  6. ^ a b "HF Distress and Safety Watchkeeping Schedule". U.S. Coast Guard Navigation Center. U.S. Coast Guard. Retrieved Oct 12, 2011.
  7. ^ "Recommendation M.541: Operational procedures for the use of digital selective-calling equipment in the maritime mobile service". International Telecommunication Union. 2015.
  8. ^ "ARRL Band Plans".
  9. ^ https://ntc5.ntc.gov.ph/wp-content/uploads/2019/09/mc-04-03-2011-authorizing-the-use-of-RF-in-times-of-emergency.pdf[bare URL PDF]
  10. ^ "IARU Emergency Telecommunications Guide" (PDF). Archived from the original (PDF) on 2018-09-20.
  11. ^ "Emergency Center of Activity Frequencies adopted by the IARU Region 1 General Conference 2005" (PDF). Archived from the original (PDF) on 2018-11-14.
  12. ^ Ulli, DK4VW - (16 May 2023). "HF - International Amateur Radio Union - Region 1". iaru-r1.org.((cite web)): CS1 maint: numeric names: authors list (link)
  13. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2013-04-08. Retrieved 2013-05-06.((cite web)): CS1 maint: archived copy as title (link)
  14. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2013-04-08. Retrieved 2013-05-06.((cite web)): CS1 maint: archived copy as title (link)
  15. ^ INC, copyright 2007 HFPACK. "HFLINK - HF Automatic Link Establishment HF ALE HF Network Ham Radio Amateur Radio HF Emergency Disaster Relief Communications". hflink.com.((cite web)): CS1 maint: numeric names: authors list (link)
  16. ^ "SHTF Survialist Radio Frequency Lists". 29 June 2013.
  17. ^ "ACMA Fact Sheet: Citizen band radio".
Categories