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Emergency position indicating radiobeacons (EPIRBs), devices which cost from $200 to about $1500, are designed to save your life if you get into trouble by alerting rescue authorities and indicating your location. EPIRB types are described below:

Type Frequencies (MHz) Description
Class A 121.5000 / 243.0000
  • Float-free, automatically-activating, detectable by aircraft and satellite.
  • Coverage is limited. An alert from this device to a rescue coordination center may be delayed
  • 4 - 6 or more hours. No longer recommended.
Class B 121.5000 / 243.0000
  • Manually activated version of Class A. No longer recommended.
Class C VHF ch 15/16
  • Manually activated, operates on maritime channels only. Not detectable by satellite.
  • These devices have been phased out by the FCC and are no longer recognized.
Class S 121.5000 / 243.0000
  • Similar to Class B, except it floats, or is an integral part of a survival craft. No longer recommended.
Category I 406.0000 / 121.5000
  • Float-free, automatically activated EPIRB.
  • Detectable by satellite anywhere in the world. Recognized by GMDSS.
Category II 406.0000 / 121.5000
  • Similar to Category I, except is manually activated.
  • Some models are also water activated.
Inmarsat E 1646.0000
  • Float-free, automatically activated EPIRB.
  • Detectable by Inmarsat geostationary satellite. Recognized by GMDSS.
  • Currently not sold in the U.S.; however, the Federal Communications Commission is considering recognizing these devices. This service will end