Which system uses the 518 kHz frequency for its international broadcasts?

• A. SART
• B. COSPAS-SARSAT
• C. ITU Channel 1212
• D. NAVTEX

Answer: (D)

NAVTEX is the system that uses 518 kHz for international broadcasts. It’s designed to automatically broadcast navigational and meteorological information to ships over coastlines, and 518 kHz is the standard international frequency so mariners can receive safety messages even if they’re far from shore. The other options describe different rescue or communications systems: SART is a radar transponder that operates with radar (not a long-range broadcast on 518 kHz) to help rescuers locate a vessel; COSPAS-SARSAT is a satellite-based distress system using 406 MHz beacons (with homing features on other frequencies), not a coastal navigational broadcast; ITU Channel 1212 is not a NAVTEX-type international broadcast system.