156.800 MHz Marine VHF Channel 16 (International Distress & Calling)
Channel 16 (156.800 MHz FM) is the universal international maritime distress, safety, and calling frequency. Monitored continuously by all sea-going vessels and global Coast Guard agencies.
156.800 MHz Marine Ch 16
International Marine VHF • VHF (Very High Frequency) • FM Mode
- Modulation Standard
- Frequency Modulation (16K0F3E / Narrowband FM)
- Channel Grid / Bandwidth
- 25 kHz international marine channel grid
- Transmitter Power (Typical)
- Vessel high power (25 W) / Low power (1 W) / Shore base (50 W)
- Polarization
- Vertical
- Signal Propagation Mode
- Maritime ground wave and tropospheric ducting
- Typical Broadcast Range
- 20 to 50 nautical miles across open water
Mandatory watchkeeping channel for all vessels over 20 meters. Initial MAYDAY, PAN-PAN, and SECURITE broadcasts are initiated here before shifting to working frequencies (e.g. Channel 22A or 06).
- Coast Guard stations issue scheduled offshore marine weather warnings (SECURITE) every 4 hours.
- SDR receivers located along coastal headlands, straits, and busy harbors capture vibrant shipping traffic.
Frequently Asked Questions about 156.800 MHz
Why do boats always keep their radios on Channel 16?
SOLAS (Safety of Life at Sea) international maritime regulations mandate that all motorized commercial vessels maintain a continuous listening watch on Channel 16 while underway.
What should a sailor do after hailing on Channel 16?
Channel 16 is for calling only. Once contact is established between ships, they must immediately switch to a working channel (such as Channel 68, 69, 71, or 72) to keep 16 clear for emergencies.
Related Radio Frequencies
121.500 MHz VHF Guard
121.500 MHz is the internationally reserved aeronautical emergency frequency (Guard). Monitored 24/7 by civilian air traffic control towers, military interceptors, and commercial airliners worldwide.
145.800 MHz ISS FM
145.800 MHz FM is the official worldwide amateur radio voice downlink aboard the International Space Station (ARISS program). When astronauts talk to schools or ham operators, their voices beam down on this VHF channel.
162.550 MHz NOAA Weather
NOAA Weather Radio All Hazards (NWR) on 162.550 MHz is a nationwide network of radio stations broadcasting continuous weather information directly from the nearest National Weather Service office.