Learn what Channel 16 is for and how to make an effective call should an emergency occur.

Every summer weekend, VHF Channel 16 is punctuated by a mélange of transmissions – some serious, some informational and some meaningless chatter. This month, I’m covering what Channel 16 is for, what Mayday, Sécurité and Pan-Pan calls mean, and most importantly, how to make an effective call should an emergency occur.

Photo Credit: On The Water Magazine

Channel 16: Do’s & Don’ts

VHF Channel 16 is the international distress frequency; it broadcasts on a frequency of 156.8 MHz and is received worldwide by any VHF radio. It is used for distress and emergency calls as well as for informational broadcasts from the Coast Guard. Channel 16 is not a radio check channel, and it’s not a conversational channel. On summer weekends, there is a constant litany from the US Coast Guard: “Please be advised Channel 16 is not a hailing frequency, it is for emergency use only.” Don’t be “that guy” asking for a radio check or having a conversation with your buddy on 16. Switch to a working channel and hold your conversation there. If you need a radio check, Channel 9 is a good place to start.

It’s also important to mention that as a mariner, you are required to keep a constant radio watch on Channel 16 and be aware of what is happening on the surrounding waters. My scan list includes both Channel 16 and the alternate Coast Guard frequency on Channel 22. I have a pencil and logbook on my console and make a habit of writing down distress calls that I hear. There are many instances where the call is not clearly heard by the Coast Guard and your written information can help them determine the location of a vessel in distress.

The three acronyms you hear all summer long on Channel 16 are French words. M’aidez (help me), Panne (breakdown), and Sécurité (security/safety) are decreasingly urgent calls used on Channel 16. The first two – Mayday and Pan-Pan – are calls for help, while the third – Sécurité – is a transmission of important navigational information.

Pan – Pan

If you boat with any frequency in summer months, you can probably recite a pan-pan call by heart. “Pan-Pan, Pan-Pan, Pan-Pan, hello all stations. This is a marine assistance request for a 19-foot center console, adrift at 41 34.52 North, 70 28.45 West in the middle of Vineyard Sound. Any mariners wishing to render assistance should contact the Coast Guard on Channel 16.”

Pan-pan is the international urgency call indicating that someone aboard a boat is declaring an urgent situation that is not an immediate threat to either the vessel or the people on board. Often, a pan-pan is issued by the Coast Guard on behalf of a smaller vessel that needs towing assistance but, on occasion, you may hear a vessel make a pan-pan call on its own.

If you have a mechanical issue on a boat, lose your navigational equipment, tangle with a lobster pot line, or experience any other non-life-threatening emergency, you should issue a pan-pan on Channel 16. As with a mayday call, communicate your boat name, your location, the nature of the problem, and the number of people on board.

As a mariner, you are required to keep a constant radio watch on Channel 16 and be aware of what is happening on the surrounding waters. Photo Credit: BoatUS


A sécurité call is an informational broadcast. The Coast Guard Notice to Mariners is typically issued as a sécurité on Channel 16 with a request to shift to Channel 22A for the full NOTAM broadcast. In fog or heavy traffic situations, a sécurité may be issued by a ferry or commercial vessel leaving or entering a harbor or narrow channel. As a prudent mariner, I issue a sécurité under those same circumstances – when the coastline is socked in by fog and I want to alert others of my coming passage through a high-traffic choke point.

I have also issued a sécurité call to other boats when I have seen dangerous debris in the water. For instance, a few years ago I came across a floating black mass of material in Muskeget Channel while heading offshore. I called the Coast Guard on Channel 16, and then issued a sécurité on Channel 68, the offshore fishing channel, so any other fishermen would be aware of that navigation hazard.

Anyone aboard a boat with a properly set up DSC-VHF radio can make a one-button distress call that automatically includes time-saving latitude and longitude location information. Photo Credit: On The Water


A mayday call is serious and should not be issued for a minor emergency. It implies a threat to life and will bring an immediate response by the Coast Guard and any other rescue agencies within range. False mayday calls are criminal offenses and can be prosecuted, leading to significant fines and reimbursement for the cost of the rescue operation. Mayday calls should be used only in life-threatening situations. Pan-pan is for a “normal” emergency.

I hope you never need to make a mayday call. I have made one and heard many dozens over the years. The difference between an effective rescue and a potential life or death situation is how accurately and clearly you get out a call for help. You must clearly communicate four critical pieces of information and keep communicating them until rescue arrives. They are:
• The name of your vessel
• Your location in latitude and longitude (GPS) coordinates
• The nature of your distress
• The number of people on board.

Each piece of information should be repeated at least three times, and the entire call should be repeated until someone responds and reads back your information correctly. Under normal circumstances, that someone will be the Coast Guard, who will take control of the radio situation and guide you through further radio procedure. In offshore situations, you may find yourself out of range of the Coast Guard and so must communicate with another boat to ask for help. In this situation, canyon fishing or offshore sailing, it’s critical that your mayday call is both accurate and complete.
It may sound silly, but I practice mayday calls in the winter and train my wife each season, especially on days when we head offshore. I have a laminated mayday procedure typed up and kept near my helm. This could be the most important radio call of your life!

Let’s go through a mayday procedure based on a real-life situation I heard years back when fishing 70 miles offshore. The situation sounded dire: “Man down. I have a person collapsed on the deck, and I am not sure he is breathing.” It involved a Coast Guard helicopter rescue and a happy ending –heat stroke and dehydration had caused a large person to faint–but it could have been a disaster because the boat with the medical emergency could not get a clear call out. Boats nearby saved the situation by getting an accurate location to the Coast Guard and then going on board to assist in running the boat during the Coast Guard rescue. After being a witness to this emergency, I started studying and practicing my procedures seriously.

So, here we go: you’re 70 miles out, it’s 2 PM, 90 degrees and high humidity. Your crewmate just landed a tuna, can’t catch his breath, doesn’t feel well, stumbles and collapses. He’s conscious, but something is clearly wrong with him. As captain, you direct your other two crew members to monitor his breathing and cool him down while you concentrate on a mayday call.

EPIRBs and Personal Locator Beacons are smart tools to have when going offshore. Photo Credit: On The Water Magazine

“MAYDAY, MAYDAY, MAYDAY. This is fishing vessel Tuna Hunter, Tuna Hunter, Tuna Hunter. My location is 40 degrees 26.34 minutes north, 70 degrees 44.81 minutes west. 40 26.34 North, 70 44.81 West, 40 26.34 North, 70 44.81 West. I have a crewmember collapsed and breathing irregularly. I need medical assistance immediately. I am a blue 32-foot center console with four people on board.“

Once this call is done, I would wait 20 seconds for any response, then repeat the same call again and again until I receive a response. If I do not get a response after a dozen tries, I would take the more drastic step of activating my EPIRB and then continuing to call. Once I got a response, I would focus on a proper and accurate latitude/longitude readback from the responder and then move on to the medical (or other) emergency.

Nothing is more important than giving an accurate and precise location. If the Coast Guard or other responder knows where you are, they can estimate a time and distance to render aid. Without that location, no help is possible. I was offshore recently and listened to a comedy show on Channel 16 where an open-ocean sailboat had run out of fuel and was looking for help in the form of a couple 5-gallon jugs of diesel fuel. The chatter told the radio all about his plight, all about his new but inaccurate fuel gauge, and all about his electronics refit, but neglected the most critical piece of information: his location!

Transmitting correct information can be the difference between life and death, so make sure someone else on the boat can read your electronic equipment and provide the correct GPS reading. I regularly drill my wife to make sure she knows which of my various screens has the accurate information and can speak those coordinates correctly on the radio.

Hearing a Mayday

Experienced captains write down coordinates if they hear a pan-pan or a mayday, and they will be prepared to stop what they are doing and come to your assistance if in range. My radio procedure is always to be scanning Channel 16, and if I hear a distress call, to press the 16 button, which locks in that channel, and get my logbook and pen ready to record any information that comes over the radio. I also mentally reference where the location is in respect to my position and prepare my crew and boat to immediately head in that direction if it is nearby.

Even in the direst circumstances, bringing a second boat to the scene can make a huge difference. Each year, many on-the-water emergencies are assisted by good Samaritans who arrive on the scene before rescue crews.

Never assume that someone else will handle a mayday call. If you hear an unanswered call, immediately get on the radio, acknowledge the mayday, boat name, its location, nature of distress, and then try to relay the mayday to the Coast Guard. I have heard exactly this scenario played out a number of times well offshore: a boat 100 miles out experiences an emergency and a boat closer to shore acts as a communications bridge, transmitting critical information from the vessel in distress to the Coast Guard and vice versa.

If a Mayday call is issued offshore and you are within range, immediately stop fishing and head for the location of the emergency. A friend of mine had a boat sink under him 20 miles south of Martha’s Vineyard. He sent out a mayday as the boat went down, and a nearby trawler immediately steamed a few miles to his location, rescuing him and his crew. A center console had an electrical fire last year even farther offshore. The crew abandoned ship due to the smoke and flames, but they were immediately saved by other fishing boats who responded quickly to the mayday call.

It’s smart to have a pencil and logbook on your console, and make a habit of writing down distress calls that you hear. Photo Credit: On The Water Magazine

DCS & MMSI – Electronic Maydays

If you have a radio built in the last 10 years, it’s likely to support Digital Selective Calling (DSC). DSC is a radio messaging protocol that, when correctly set up, sends out your Maritime Mobile Service Identity (MMSI) and GPS location as a coded message on multiple radio frequencies. The means of encoding provides a more powerful signal than is present in a verbal radio transmission. You can typically initiate a DSC distress call by turning your radio to Channel 16 and pressing a large red DSC or DISTRESS button after removing its protective cover.

There is a caveat to this “magic button,” and it is a large technical caveat. First, you must register your MMSI or radio identity with the FCC. This can easily be done online with either Sea Tow or BoatUS and is free if you are a member. The next step is to enter that MMSI number into your radio correctly. Finally, you must link a pair of radio wires either directly to your GPS or to a NMEA 2000 bridge.

Only after all three of these steps are done will that big red button correctly summon help.

The Most Important Call

I hope you never have a situation on the water that requires a mayday call; it means something is terribly wrong and you and your crew are at imminent risk. If you do have to make a call, remember, the radio is your lifeline to help, and help can only get to you if you:
• Identify your boat
• Give an accurate location in latitude and longitude
• Communicate the problem or injury that is occurring
• Give an accurate count of people on the boat.

Practice makes perfect. Read up on mayday protocol and practice it on a rainy day. It might just save someone’s life!

Article by Larry Backman from On The Water Magazine

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