My 5-year old son loves sending out an SOS signal using a toy Morse code generator (wired, don't worry about false alarms for real authorities).

He has learned to send the SOS signal and was asking me to send a response to him to let him know that help is on the way.

What Morse code should I respond with in a real life situation when I hear a distress call on radio?

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    $\begingroup$ How about a real life story? Here is one where the proper response was merely to call 911. heraldnet.com/news/hiker-safe-with-help-of-ham-radio $\endgroup$
    – K7PEH
    Commented Mar 11, 2019 at 16:17
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    $\begingroup$ I know he's only 5, but it would still be a good idea to tell him that either SOS or Mayday radio transmissions must only be sent during a genuine emergency involving aircraft or ships at sea. From Wikipedia: "[distress signals] must only be used where there is grave and imminent danger to life. Otherwise, urgent signals such as pan-pan can be sent. Most jurisdictions have large penalties for false, unwarranted or prank distress signals". Those penalties are jail time and very large fines. $\endgroup$ Commented Mar 11, 2019 at 19:45
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    $\begingroup$ @MikeWaters Only those involving airplanes or ships at sea? I thought it was any situation where your life or others lives were in danger (where it could help at least). For example, if you're lost in the desert with limited supplies and you have a portable rig on you, would it not be appropriate to send SOS? $\endgroup$ Commented Mar 11, 2019 at 21:31
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    $\begingroup$ @DuncanXSimpson One might think so, but that is definitely not the case. The key here is grave and imminent danger to life. Governments take that as (for example) "Our ship is sinking fast!". Check out SOS and Mayday Wikipedia articles. See Pan-Pan. $\endgroup$ Commented Mar 11, 2019 at 21:52
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    $\begingroup$ @MikeWaters I see. In that case, would it be appropriate if, say, you were surrounded by a forest fire that was closing in? That's the only other situation I can think of where it could be appropriate on land. $\endgroup$ Commented Mar 11, 2019 at 22:04

5 Answers 5


Since you're simulating the situation with non-transmitting equipment, you get the play the part of actual emergency agencies. You'd start by asking the SOS caller to identify themselves (call sign, ship name, etc.) and give their location and the nature of the emergency.

Of course, unless your 5 year old knows a lot more Morse than just SOS, that's where the exchange will end -- but this is a good way to get him interested in learning the whole alphabet (if he hasn't), getting his speed up, learning prosigns, and so forth.

In a real life situation, the FCC says you should respond to the caller and ask what assistance is needed -- pretty much what you'll do in simulation with your son. Find out what's the emergency, where the caller is located (latitude and longitude, map grid, or town and address), etc.

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    $\begingroup$ Thanks. Guy knows ICAO phonetics and can easily identify himself as Mike Sierra Delta with Mayday Mayday Mayday. $\endgroup$ Commented Mar 11, 2019 at 13:37

Since this is all for a bit of fun, you could respond with the typical Morse Code response to indicate that the last transmission was successfully received: R:


Some operators stylize this as two R's sent consecutively. You could also use your "Dad" call sign by appending "de DAD":

-••  •    -••  •-  -••

which means this transmission is "from Dad".

As others have pointed out, in a real situation the response would either be asking for clarifying information (e.g. a location or nature of emergency) or it would be a confirmation that help is on the way. If I were responding, I would end my transmission with "de W9IQ" to indicate my FCC assigned call.

  • $\begingroup$ How about ACK? $\endgroup$ Commented Mar 11, 2019 at 15:52
  • $\begingroup$ @HankyPanky "ACK" isn't typically used with Morse Code but it is only for fun so feel free. A more likely response for an amateur radio operator with either be the indicated "R" or "QSL" meaning message received. $\endgroup$
    – Glenn W9IQ
    Commented Mar 11, 2019 at 16:09
  • $\begingroup$ Perfect. I will discuss R and QSL both with him. Its good to use those because they can someday be real useful for him in real life, as opposed to non standard phrases. $\endgroup$ Commented Mar 11, 2019 at 16:24

First, let's be very clear that making a false distress call is a federal crime carrying sanctions of up to six years imprisonment, and a fine of $250,000.

Second, there is no commercial or maritime use of Morse now, so distress calls use "Mayday Mayday Mayday" at the beginning and end. You are extremely unlikely to hear a Morse distress call or need to respond to one. Maritime Morse stations stopped operation on July 12, 1999, almost twenty years ago.

When someone who is not a first responder or dispatcher receives a distress call, they need to start writing down information to forward to first responders. If they don't provide it, and they may be scared and not thinking straight, you need to interview them.

Be calm and clear. If a better-prepared station steps in to help, let them do it.

For a maritime distress call, collect this information. A land call would be similar. This is a script for the person making the call, so you would walk them through this.

First, write down the local time (your own clock). If you have UTC, use that.

  • Distress signal "MAYDAY", spoken three times.
  • The words "THIS IS", spoken once.
  • Name of vessel in distress (spoken three times) and call sign or boat registration number, spoken once.
  • Repeat "MAYDAY" and name of vessel, spoken once.
  • Give position of vessel by latitude or longitude or by bearing (true or magnetic, state which) and distance to a well-known landmark such as a navigational aid or small island, or in any terms which will assist a responding station in locating the vessel in distress. Include any information on vessel movement such as course, speed and destination.
  • Nature of distress (sinking, fire etc.).
  • Kind of assistance desired.
  • Number of persons onboard.
  • Any other information which might facilitate rescue, such as length or tonnage of vessel, number of persons needing medical attention, color hull, cabin, masks, etc.
  • The word "OVER"

From: https://www.navcen.uscg.gov/?pageName=mtBoater

You should practice copying text, including asking for repeats and phonetic spelling.

The best practice is participating in drills and public service events for your local ARES/RACES emergency communication group.

Here is a recorded VHF marine distress call. You can find more of these on YouTube.


For more information about maritime Morse, start with the Night of Nights, which runs maritime Morse one day per year on July 12.



To respond to a received Morse SOS by radio requires a transmit system and operator able to do that.

Normally a transmit station license issued by the appropriate regulating agency having jurisdiction for that receive location is required to operate such a transmitter.

If no such transmit capabilities are available, then relaying the details of the SOS message to an appropriate, emergency response organization is about the best recourse available.

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    $\begingroup$ Relative to licensing, it's worth noting that FCC explicitly permits anyone do whatever is necessary with whatever radio equipment they can access in order to save lives or property in an actual emergency. License or no license, any band you can access that might get through, any mode your transmitter can emit. In an emergency. $\endgroup$
    – Zeiss Ikon
    Commented Mar 12, 2019 at 15:53
  • $\begingroup$ That is technically true, but not actually useful. First, 90+% of emergency calls are not life or property emergencies. Second, if you interfere with other official traffic, you may still be fined. Third, if you don't use your radio in non-emergency situations, you won't be able to use it well in emergencies. So the whole "non-licensed emergency" thing not useful for emergency preparation. Because it isn't "preparation". It is just buying a radio. $\endgroup$ Commented Mar 12, 2019 at 17:30

I received such notification while listening on 2182 kHz and phoned the Coast Guard with the broadcast-in-blind details I copied.

Their Coast station told the ship in distress to call the commercial station that was copying them! I called the Coast Guard back to notify them that I couldn't respond and was not a maritime station.

Happy ending, ship met by coast guard, dewatering pumps delivered and ship pumped out in time to avert sinking, ship towed to nearest port.

  • $\begingroup$ Great answer, thank You! $\endgroup$ Commented Jul 6, 2020 at 23:46
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    $\begingroup$ Welcome to ham.stackexchange.com! $\endgroup$
    – rclocher3
    Commented Jul 7, 2020 at 22:29

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