How to Make a Mayday Call

Posted: March 1, 2011

By: U.S. Coast Guard Office of Search and Rescue

A lot of mishaps can occur out on the water, most of which are more inconvenient and embarrassing than anything else. But when lives are on the line – your boat is on fire or sinking rapidly with people on board, or someone is in imminent danger of dying without immediate medical assistance – you want every available resource dispatched to your position. A mayday call will bring that kind of help. Not only will the U.S. Coast Guard respond, but the Coast Guard may notify state and local search-and-rescue units in your vicinity and ask them to respond as well. The Coast Guard will also transmit an Urgent Marine Information Broadcast over marine-band VHF-FM radio Channel 16, notifying all vessels in the area of your emergency.

A mayday – the term is derived from the French venez m’aider, meaning “Come. Help me.” – should be transmitted if possible via marine-band VHF-FM radio Channel 16 or 2182 kHz MF/SSB. Emergencies can go from bad to worse in seconds, so try to get as much information across in as little time as possible. International Maritime Organization protocols call for beginning the transmission with the word “mayday” repeated three times, followed by the name and number of your vessel, its position, the nature of the emergency and the number of people on board, their condition and whether they are wearing life jackets. If you have a marine GPS, relate the latitudinal and longitudinal coordinates. If not, state your distance and magnetic or true bearing from the closest navigational landmark. If time allows, you can also relay your departure point, departure time and the speed at which you were traveling.

All of these can help rescuers locate you. (See sidebar for step-by-step instructions.)

Once you’ve made contact and given your information, Coast Guard Search and Rescue planners will keep you advised of their actions and give you an estimate of when rescue units will arrive. If you have a medical emergency, assign someone to monitor the radio from the time you make the call until the rescuers are on the scene. The Coast Guard will direct you to the nearest safe haven and advise you of what actions you should take in the interim.

The Rescue Coordination Center or local Coast Guard station may deploy a helicopter, rescue vessel or nearby commercial ship, depending on your location, the local weather, the availability of crew and equipment, and the nature of the emergency.

When the Coast Guard receives your mayday, the mission coordinator will determine your degree of danger by considering several factors: the nature of your situation and the gear on board your vessel (e.g., first-aid kit, food, water, life jackets), the accuracy of your position, the tide, visibility, current and sea conditions, present and forecast weather, special considerations (e.g., age/health of those on board), whether you have reliable communications, the degree of fear in those on board and the potential for the situation to deteriorate further.

If a helicopter is dispatched, be sure to secure all loose items on deck, as helicopter rotor wash is powerful, and unsecured items may turn into flying projectiles. Lower and secure any sails, remove any equipment that may snag the line attached to the rescue basket and make sure everyone is wearing a

life jacket. The helicopter is likely to approach your boat on the port

stern quarter, because it gives the pilot optimal visibility from the cockpit. So unless instructed otherwise, set your course so the wind is 45 degrees off your port bow. Remember, never shine a light or strobe directly toward the helicopter, and never fire flares in its vicinity. Wait for the rescuers to tell you what to do, and then do it. In any emergency situation, listening may be your most important skill.

Recently, the Coast Guard began implementing a new command, ­control and communications system – Rescue 21 – which is being installed in stages across the U.S. It will vastly improve the Coast Guard’s ability to save lives and property.

(For more information, visit

strategy.asp.) Harnessing global positioning and other advanced communications technology, this fully integrated system will cover coastlines, navigable rivers and waterways in the continental U.S., Alaska, Hawaii, Guam and Puerto Rico, and help eliminate 88 known radio coverage gaps.

No new equipment is needed for you to benefit from Rescue 21, but you can help improve response time by upgrading to a marine-band VHF-FM radio equipped with digital selective calling (DSC). When properly registered with a Maritime Mobile Service Identity (MMSI) number and interfaced with GPS, the DSC radio signal transmits vital information – vessel name, position, owner/operator’s name and the nature of the distress (if entered) – with one push of a button, and a reply should be received almost immediately. BW

The U.S. Coast Guard reminds all boaters to “Boat Responsibly!” For more tips on boating safety, visit

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