VHF Radio Channels
Authority: ITU Radio Regulations / US Coast Guard Navigation Center
VHF Maritime radios operate between 156.000 and 162.025 MHz. Channel 16 (156.800 MHz) is the international emergency distress and calling channel. Channel 13 (156.650 MHz) is mandatory for bridge-to-bridge navigation.
| Channel # | Frequency (MHz) | Primary Use / Purpose | Mandatory Monitoring Duty |
|---|---|---|---|
| Channel 16 | 156.800 MHz | International Distress, Safety & Calling | Mandatory watch for all vessels over 20m |
| Channel 13 | 156.650 MHz | Bridge-to-Bridge Navigation Safety | Commercial vessel navigation communication |
| Channel 06 | 156.300 MHz | Inter-vessel Search & Rescue (SAR) | Coordinating SAR operations |
| Channel 22A | 157.100 MHz | US Coast Guard Safety Broadcasts | Maritime Safety Information (MSI) |
Why Channel 16 Is Universal
VHF marine radio's channel plan is coordinated internationally by the ITU precisely so that any vessel, regardless of flag or home port, can hail any other vessel or shore station on a frequency everyone is already listening to. Channel 16 (156.800 MHz) fills that role as the designated international distress, safety, and calling frequency, and vessels are expected to monitor it continuously while underway so a mayday call reaches anyone within range immediately, without needing to know in advance which channel a nearby vessel might be using.
The convention on Channel 16 is to make first contact there and then immediately shift to a working channel for the actual conversation, keeping 16 clear for the next distress or safety call. This same discipline underlies the broader Global Maritime Distress and Safety System (GMDSS), which layers newer digital selective calling and satellite alerting on top of the original voice-channel distress procedures.