US VHF Radio & Distress Calls

Prerequisites

• The phonetic alphabet and how to say numbers clearly on the radio.
• Knowing how to give your position as latitude and longitude, or as a bearing and distance from a charted point.
• A basic idea of what a VHF radio does: line-of-sight voice radio between boats and shore.

Learning Objectives

This lesson covers the communications part of the ASA 103 Coastal Cruising standard, for US waters. By the end of it you will be able to:

• Say when a US recreational boat needs a radio licence, and where to get an MMSI.
• Use the right channel for calling, talking to other boats, bridge-to-bridge traffic and the Coast Guard.
• Find the NOAA Weather Radio channels.
• Make Mayday, Pan-Pan and Securite calls in the right order.
• Send a DSC distress alert, and avoid false alerts.
• Register a 406 MHz EPIRB or PLB with NOAA.

Licensing and the MMSI

In most countries you need an operator's certificate to use a marine VHF, which is why RYA students take the SRC course. The US is different.

• A recreational boat that is not required by law to carry a radio, and that uses VHF only in US waters, does not need an FCC ship station licence. Its operator does not need an individual licence either.
• You do need an FCC licence if you sail to foreign ports, or if you carry MF/HF single sideband or satellite radio. Plan for this before cruising to the Bahamas, Mexico or Canada.

A DSC (Digital Selective Calling) radio needs a 9-digit MMSI (Maritime Mobile Service Identity) programmed into it. Without one, the red distress button cannot tell rescuers who you are.

• For domestic-only recreational use, you can get a free or low-cost MMSI from BoatUS, Sea Tow or the US Power Squadrons. These numbers are only valid in US waters.
• If you need an FCC ship station licence, the MMSI comes from the FCC and works internationally.
• Enter the MMSI carefully. Most radios accept it only once or twice, and a wrong entry often means sending the radio back to the manufacturer.
• Keep your registration up to date with your boat's details and emergency contacts. Rescuers use it.

The US Channel Plan

These are the channels you will use most often in US waters (USCG Navigation Center table):

How to use them:

1. Make an initial call to another boat on 16 or 9.
2. As soon as you have contact, agree to move to a working channel: "Switch to six-eight".
3. Finish your conversation there, then return to watching 16.

When the radio is on and you are not talking on another channel, the Coast Guard asks boaters to listen on channel 16 or 9.

US and international mode. Some channels, such as 22A and 78A, are US-only "A" channels. Most radios have a US/INT/CAN setting. Leave it on US in American waters, or you will not hear Coast Guard broadcasts on 22A. The newer four-digit numbers (1022, 1078) are the international names for the same channels.

NOAA Weather Radio

Weather channels WX1 to WX7 (162.400–162.550 MHz) carry NOAA Weather Radio, a continuous automated broadcast of local forecasts, warnings and observations. They are receive-only. Most marine VHFs have a WX button and a weather alert mode that sounds an alarm when the National Weather Service issues a warning. The channel number used varies by area, so find the one with the clearest signal for your sailing ground.

The Coast Guard announces urgent marine information and storm warnings on channel 16, then reads the details on 22A.

Distress: Mayday

Use MAYDAY only when a vessel or person is in grave and imminent danger and needs immediate help: sinking, fire out of control, a person overboard who cannot be recovered, a life-threatening injury.

Call on channel 16 at high power:

1. "MAYDAY, MAYDAY, MAYDAY."
2. "This is sailing vessel Osprey, Osprey, Osprey" (plus your MMSI if you have one).
3. "MAYDAY, Osprey."
4. Position: latitude and longitude, or bearing and distance from a known point.
5. Nature of distress: "We are taking on water and sinking."
6. Help needed: "Require immediate assistance."
7. Number of people aboard, and any injuries.
8. Other information: description of the boat, "abandoning to life raft", and so on.
9. "Over."

Then wait and listen. If there is no reply, repeat the call. Position comes first because a call that gets cut off is still useful if the position got through.

Making a false Mayday is a federal crime. So is a "Mayday radio check" on channel 16, which the Coast Guard treats as a hoax call.

Urgency and Safety Calls

PAN-PAN (pronounced "pahn-pahn") is for an urgent situation that is not yet life-threatening: a dismasting, a disabled engine near rocks, a medical problem that needs advice. Use the same structure as a Mayday, starting with "PAN-PAN" three times.

SECURITE (pronounced "say-cure-ee-tay") is for a safety message about navigation or weather, such as a floating hazard, a large tow in a narrow channel, or the Coast Guard's broadcast notices. Make the call on 16, then give the details on a working channel.

DSC Distress Alerts

A DSC radio connected to a GPS can send a digital distress alert with one button:

• Lift the red cover and hold the DISTRESS button for about five seconds. If there is time, select the nature of distress first.
• The alert sends your MMSI and position on channel 70. It repeats until a station acknowledges it.
• Then the radio switches to channel 16. Follow up with a full voice Mayday.

Never test the distress button. If you send a false alert, cancel it at once by voice on channel 16: give your boat's name and MMSI and say the alert was sent in error.

EPIRBs and PLBs

A 406 MHz EPIRB (on the boat) or PLB (on a person) sends a distress signal by satellite through the international COSPAS-SARSAT system. It works far beyond VHF range.

• In the US, registration with NOAA is required by law and is free. Register at beaconregistration.noaa.gov.
• The registration links your beacon's unique ID to your boat, emergency contacts and trip details, so rescuers know who they are looking for.
• Update it when you change boats, phone numbers or ownership.

Worked Example: Engine Failure Near a Shoal

You are motoring into an inlet on a falling tide when the engine dies. The wind is light and pushing you slowly towards a shoal 400 yards away. No one is hurt, and the boat is not taking on water.

1. This is urgent but not grave and imminent danger, so a Pan-Pan, not a Mayday.
2. Prepare to anchor. Then call on channel 16: "PAN-PAN, PAN-PAN, PAN-PAN. All stations, all stations, all stations. This is sailing vessel Osprey. Position: 300 yards southwest of green buoy 5, at the entrance to the inlet. Engine failure, drifting towards the shoal. Requesting a tow. Three people aboard. Over."
3. The Coast Guard replies and asks you to switch to 22A. You do, and give more details there.
4. While you wait, anchor if you can, put on life jackets and watch the drift.

Common Mistakes

• Holding conversations on channel 16 instead of moving to a working channel.
• Leaving the radio in International mode in US waters and missing broadcasts on 22A.
• Calling Mayday for a problem that is a Pan-Pan, or calling for a radio check on 16.
• Not programming the MMSI, so the DSC distress button sends no identity.
• Forgetting the GPS connection, so DSC alerts carry no position.
• Not registering, or not updating, an EPIRB or PLB.

Summary

• A recreational boat in US waters needs no FCC licence for VHF. Sailing abroad or using SSB requires one.
• A DSC radio needs an MMSI, from BoatUS, Sea Tow or the US Power Squadrons for domestic use, or from the FCC.
• Use 16 for distress and calling, 9 for boater calling, 13 for ships, 22A for the Coast Guard, and 68, 69, 71, 72 or 78A for conversations.
• WX channels carry NOAA Weather Radio.
• Mayday is for grave and imminent danger, Pan-Pan for urgent problems, Securite for safety information.
• A DSC alert sends your MMSI and position on 70. Follow up by voice on 16.
• Register 406 MHz beacons with NOAA. It is the law and it is free.

Check Your Understanding

1. Do you need an FCC licence for a fixed VHF on a recreational sailboat used only in US waters? No. You do if you sail to foreign ports or use SSB or satellite radio.
2. You want to talk to a friend's boat. Which channel do you call on, and where do you move? Call on 16 or 9, then switch to a non-commercial working channel such as 68, 69, 71 or 72.
3. Which channel do large ships monitor for bridge-to-bridge communications? Channel 13.
4. Your mast breaks offshore, but no one is hurt and the boat is not sinking. Which call do you make? A Pan-Pan.
5. What does a DSC distress alert send, and what must you do after sending it? It sends your MMSI and position on channel 70. Follow it with a voice Mayday on channel 16.

Sources

• https://www.navcen.uscg.gov/radio-information-for-boaters
• https://www.navcen.uscg.gov/us-vhf-channel-information
• https://www.navcen.uscg.gov/gmdss-frequently-asked-questions
• https://www.boatus.com/MMSI/MMSI/AboutUs
• https://www.sarsat.noaa.gov/emergency-406-beacons/