International distress frequency

International distress frequencies, currently in use are:

• 2182 kHz for medium range maritime voice use. The US Coast Guard has said “beginning August 1st, 2013 the Coast Guard would no longer monitor 2182 kHz”,[4] as have many other coast guard services.
• Several HF maritime voice frequencies exist for long-distance distress calls:[5]
  • 4.125 MHz
  • 6.215 MHz
  • 8.291 MHz
  • 12.290 MHz
  • 16.420 MHz
• 121.5 MHz is the civilian aircraft emergency frequency or International Air Distress frequency. It is used by civilian distress radiobeacons; however, the Cospas-Sarsat system no longer monitors the frequency.
• 243 MHz for NATO military aircraft emergency frequencies
• Marine VHF radio Channel 16 (156.8 MHz) for short range maritime use
• 406 MHz to 406.1 MHz is used by the Cospas-Sarsat international satellite-based search and rescue (SAR) distress alert detection and information distribution system
• 462.675 MHz is a UHF mobile distress and road information calling frequency allocated to the General Mobile Radio Service and used throughout Alaska and Canada for emergency communications; formerly called Orange Dot in the 1960s, “GMRS 675” or Channel 6 on mobile radios today. Its bandwidth can vary between 12.5, 25 and 50 kHz, and is also allocated to Ch. 20 on 22-channel FRS/GMRS “blister pack” radios. It can have a repeater input frequency of 467.675 MHz, and a tone squelch of 141.3 Hz.

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

• 2.1875 MHz
• 4.2075 MHz
• 6.312 MHz
• 8.4145 MHz
• 12.577 MHz
• 16.8045 MHz
• 156.525 MHz, Marine VHF radio Channel 70

• Emergency Centre of Activity (ECOA) frequencies informally established by the International Amateur Radio Union regional organizations (frequencies shown in kHz):

• Emergency/Disaster Relief Interoperation Voice Channels of the amateur radio Global ALE High Frequency Network:
  • 3791.0 kHz USB
  • 7185.5 kHz USB
  • 10145.5 kHz USB
  • 14346.0 kHz USB
  • 18117.5 kHz USB
  • 21432.5 kHz USB
  • 24932.0 kHz USB
  • 28312.5 kHz USB
• Citizens band (CB) radio (not available in all countries)
  • Emergency channels 9 (27.065 MHz AM) and 19 (27.185 MHz AM)