Marine VHF Channel Reference

Distress and safety

Channel 16 (156.800 MHz) is the international distress, safety, and calling frequency. Every vessel with a VHF must monitor 16 whenever the radio is on. Use it for Mayday, Pan-Pan, Sécurité, and initial hails — then move to a working channel.

Channel 22A is the USCG working channel after they direct you off 16. Pre-program it as a quick-recall channel.

Channel 70 is DSC (digital selective calling) only — never voice on 70. Modern radios manage this automatically when you press the distress button.

Hailing channels

Channel 16: international hailing. Always available. Keep transmissions to under 30 seconds — establish contact, then move.

Channel 9: USCG-requested alternate for recreational hailing in many regions. Helps keep 16 clear for actual distress. Many marinas now monitor 9 instead of 16.

Channel 78A: another common recreational hailing/working channel in the southeastern US.

Recreational working channels

After hailing, switch to one of: 68, 69, 71, 72, 78A. These are recreational working channels in US waters. Pick one that's clear when you switch.

Don't camp on a working channel for hours — others are trying to use them. Long social conversations belong on a cell phone.

Commercial and bridge-to-bridge

Channel 13 is bridge-to-bridge navigation safety, 1-watt low power. Monitor 13 in busy commercial waterways. Listen for ship-to-ship passing arrangements ('one whistle' = port-to-port pass, 'two whistle' = starboard-to-starboard).

Channel 67 is the alternate bridge-to-bridge channel in the lower Mississippi.

Channels 1, 5, 12, 14, 63, 65, 66, 73, 74, 77, 79, 80: port operations and traffic — vessel traffic services, pilots, locks, and terminals. Local listings vary; check the USCG Local Notice to Mariners for your region.

Weather and special services

WX 1, WX 2, WX 3, WX 4: NOAA Weather Radio broadcasts (receive only). Continuous weather and forecast loops, with severe-weather alerts. Always pre-programmed.

Channel 06: inter-ship safety, used in SAR operations and convoy traffic.

Channel 27: marine operator (largely defunct in the US since cell coverage; still active in some areas).

Why some channels have an 'A' suffix

International marine VHF channels use duplex pairs — transmit on one frequency, receive on another, allowing simultaneous two-way conversation through a coast-station repeater.

US 'A' channels are simplex variants of the same channel number — both stations transmit and receive on the same single frequency (the ship side of the international pair).

Practical effect: if you're cruising US waters and switch to 'channel 22,' you actually need 22A. International boats arriving in US waters may need to switch their radio to USA mode in the menu.

Building your scan list

A useful default scan list for US coastal cruising: 16, 09, 13, 22A, 68, 70 (DSC monitoring), and the local working channel for your marina or yacht club. Most fixed-mount radios let you tag favorites with one button.

Dual-watch toggles between 16 and one priority channel — handy when you're working a fishing tournament on 72 or coordinating a dinghy fleet on 78A but still need 16 in the background. Tri-watch adds a third channel; useful in busy ports like New York Harbor or Norfolk where you want 16, 13 (commercial bridge-to-bridge), and a working channel simultaneously.

On the Great Lakes and inland rivers, the priority channels shift — Western Rivers traffic favors 13 and 67, and many lock operators monitor 14. Local Notice to Mariners lists the priority channels for each USCG district.