What is the only authorized type of EPIRB for use in the United States as of January 1, 2007?

• A. 121.5 MHz EPIRB
• B. 406 MHz EPIRB
• C. 243 MHz EPIRB
• D. 2-way VHF EPIRB

Answer: (B)

The main idea is understanding how distress beacons connect to search-and-rescue systems. In the United States, the up-to-date standard by 2007 is the 406 MHz EPIRB. These beacons transmit a digital signal that is uniquely identified in the international COSPAS-SARSAT network, and if the unit includes a GPS receiver, it sends precise location data as well. This combination lets rescue authorities alert quickly and pinpoint where help is needed, reducing search time and improving accuracy.

Older, non-digital or non-satellite-capable beacons—like 121.5 MHz or 243 MHz models—don’t initiate satellite alerts. They may help rescuers once you’re already located, but they aren’t the primary means of triggering a nationwide or global distress alert. A 2-way VHF EPIRB isn’t the standard distress beacon used for satellite-based rescue at that time, so it wouldn’t be the authorized type for initiating the SOS in the U.S. in 2007.

So, the 406 MHz EPIRB is the only authorized type because it activates the satellite-based alert with a trackable identity (and location if GPS-equipped), which is essential for fast, reliable rescue.