You may only have seconds to send a distress call. Here’s what you should do:
Procedure for VHF Channel 16 MAYDAY:
- If you have a VHF marine radio, tune it to channel 16. Unless you know you are outside VHF range of shore and ships, call on channel 16 first.
- 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”
Stay by the radio if possible. Even after the message has been received, the Coast Guard can find you more quickly if you can transmit a signal on which a rescue boat or aircraft can home.
THIS IS BLUE DUCK-BLUE DUCK-BLUE DUCK WA1234 MAYDAY THIS IS BLUE DUCK
CAPE HENRY LIGHT BEARS 185 DEGREES MAGNETIC-DISTANCE 2 MILES
STRUCK SUBMERGED OBJECT
NEED PUMPS-MEDICAL ASSISTANCE AND TOW
THREE ADULTS, TWO CHILDREN ONBOARD
ONE PERSON COMPOUND FRACTURE OF ARM
ESTIMATE CAN REMAIN AFLOAT TWO HOURS
BLUE DUCK IS THIRTY TWO FOOT CABIN CRUISER-WHITE HULL-BLUE DECK HOUSE
OVER Repeat at intervals until an answer is received.
Transmission of DSC Distress Alert
A distress alert should be transmitted if, in the opinion of the Master, the ship or a person is in distress and requires immediate assistance.
A DSC distress alert should as far as possible include the ship’s last known position and the time (in UTC) when it was valid. The position and the time may be included automatically by the ship’s navigational equipment or may be inserted manually.
The DSC distress alert is transmitted as follows: (for DSC equipped VHF radios)
Standard VHF operation (example is from a Standard Horizon GX1100S model VHF):
- Locate and lift (spring loaded) or remove the small red plastic DSC button cover on the radio
- Press and hold the DSC button
- The Distress menu will appear on the screen
- A 30 second count down will appear on the screen
- Watch transceiver for any acknowledgments (radio should still be receiving any calls on ch 16 automatically)
- If acknowledgement is received switch to ch 16 and report your distress situation
- If no acknowledgment is received the distress alert will repeat in 4 minute intervals
in accordance with the DSC equipment manufacturer’s instructions;
- transmit the DSC distress alert:
- prepare for the subsequent distress traffic by tuning the transmitter and the radiotelephony receiver to the distress traffic channel in the same band, i.e. 2 182 kHz on MF, channel 16 on VHF, while waiting for the DSC distress acknowledgment.
- NOTE – Some maritime MF radiotelephony transmitters shall be tuned to a frequency 1700 Hz lower than 2187.5 kHz, i.e. 2185.8 kHz, in order to transmit the DSC alert on 2187.5 kHz.
Actions on Receipt of a Distress Alert
Ships receiving a DSC distress alert from another ship should normally not acknowledge the alert by DSC since acknowledgment of
a DSC distress alert by use of DSC is normally made by coast stations only.
Only if no other station seems to have received the DSC distress alert, and the transmission of the DSC distress alert continues, the ship should acknowledge the DSC distress alert by use of DSC to terminate the call. The ship should then, in addition, inform a coast station or a coast earth station by any practicable means.
Ships receiving a DSC distress alert from another ship should also defer the acknowledgment of the distress alert by radiotelephony for a short interval, if the ship is within an area covered by one or more coast stations, in order to give the coast station time to acknowledge the DSC distress alert first.
Ships receiving a DSC distress alert from another ship shall:
watch for the reception of a distress acknowledgment on the distress channel (2187.5 kHz on MF and channel 70 on VHF);
- prepare for receiving the subsequent distress communication by tuning the radiotelephony receiver to the distress traffic frequency in the same band in which the DSC distress alert was received, i.e. 2182 kHz on MF , channel 16 on VHF;
- acknowledge the receipt of the distress alert by transmitting the following by radiotelephony on the distress traffic frequency in the same band in which the DSC distress alert was received, i.e. 2182 kHz on MF, channel 16 on VHF:
- the 9-digit identity of the ship in distress, repeated 3 times,
- “this is”,
- the 9-digit identity or the call sign or other identification of own ship, repeated 3 times,
- “RECEIVED MAYDAY”.
NOTE – Ships out of range of a distress event or not able to assist should only acknowledge if no other station appears to acknowledge the receipt of the DSC distress alert.
On receipt of a DSC distress acknowledgment the ship in distress should commence the distress traffic by radiotelephony on the distress traffic frequency (2182 kHz on MF, channel 16 on VHF) as follows:
- “this is”,
- the 9-digit identity and the call sign or other identification of the ship,
- the ship’s position in latitude and longitude or other reference to a known geographical location,
- the nature of distress and assistance wanted,
- any other information which might facilitate the rescue.
Transmission of a DSC Distress Relay Alert
A ship knowing that another ship is in distress shall transmit a DSC distress relay alert if
- the ship in distress is not itself able to transmit the distress alert,
- the Master of the ship considers that further help is necessary.
The DSC distress relay alert process in general is as follows:
- tune the transmitter to the DSC distress channel (2187.5 kHz on MF, channel 70 on VHF),
- select the distress relay call format on the DSC equipment, key in or select on the DSC equipment keyboard:
- All Ships Call or the 9-digit identity of the appropriate coast station,
- the 9-digit identity of the ship in distress, if known,
- the nature of distress,
- the latest position of the ship in distress, if known,
- the time (in UTC) the position was valid (if known),
- type of subsequent distress communication (telephony);
- transmit the DSC distress relay call,
- prepare for the subsequent distress traffic by tuning the transmitter and the radiotelephony receiver to the distress traffic channel in the same band, i.e. 2182 kHz on MF and channel 16 on VHF, while waiting for the DSC distress acknowledgment.
Acknowledgment of a DSC Distress Relay Alert Received From a Coast Station
Coast stations, after having received and acknowledged a DSC distress alert, may if necessary, retransmit the information received as a DSC distress relay call, addressed to all ships, all ships in a specific geographical area, a group of ships or a specific ship.
Ships receiving a distress relay call transmitted by a coast station shall not use DSC to acknowledge the call, but should acknowledge the receipt of the call by radiotelephony on the distress traffic channel in the same band in which the relay call was received, i.e. 2182 kHz on MF, channel 16 on VHF.
Acknowledge the receipt of the distress alert by transmitting the following by radiotelephony on the distress traffic frequency in the same band in which the DSC distress relay alert was received:
- the 9-digit identity or the call sign or other identification of the calling coast station,
- “this is”,
- the 9-digit identity or call sign or other identification of own ship,
- “RECEIVED MAYDAY”.
Cancellation of an Inadvertent Distress Alert (Distress Call)
A station transmitting an inadvertent distress alert shall cancel the distress alert using the following procedure:
- Immediately transmit a DSC “distress acknowledgment” in accordance with Recommendation ITU-R M.493, 8.3.1 e.g. with own ship’s MMSI inserted as identification of ship in distress. (NOTE: This feature is not yet generally available on DSC-equipped radios)
- Cancel the distress alert aurally over the telephony distress traffic channel associated with each DSC channel on which the “distress call” was transmitted.
- Monitor the telephony distress traffic channel associated with the DSC channel on which the distress was transmitted, and respond to any communications concerning that distress alert as appropriate.
Pan-pan (repeated 3 times) is the international urgency signal that is used as a preface to a VHF transmission when the safety of a person or the boat is in serious jeopardy but no immediate danger exists, but it could escalate into a mayday situation. For example, pan-pan is used in situations in which the boat has a slow leak or the engines are disabled and the boat is drifting toward a rocky shore.
Sécurité (repeated 3 times) is a safety signal used as a preface to announce a navigation safety message. This may be an approaching storm, a navigation light failure, a submerged log in a harbor entrance or military gunnery practice in the area.
If you hear a distress call…
If you hear a distress message from a vessel and it is not answered, then you must answer. If you are reasonably sure that the distressed vessel is not in your vicinity, you should wait a short time for others to acknowledge.
Your VHF radio is intended mainly for short range communications, generally 5-10 miles, and at least 20 miles to a USCG station. To communicate at longer ranges, you will normally need a satellite telephone or an MF/HF marine radiotelephone. Marine radiotelephone equipment normally operates between 2 – 26 MHz using single sideband emissions. MF/HF marine radiotelephones can also be used to receive high seas weather broadcasts, and by using a computer and a special interface provided by some coast stations, can provide Internet email.
Tune your HF radiotelephone to an HF channel guarded by the Coast Guard, and repeat your mayday call. Activate your EPIRB.
Boater Calling Channel (VHF Channel 9)
We recommend boaters normally keep tuned to and use channel 16 in those waters unless otherwise notified by the Coast Guard.
Procedure for Calling A Ship by Radio
You may use channel 16 to call a ship or shore station, but if you do so, you must, must be brief! We recommend this same procedure be used over channel 9, if channel 9 is used as a calling channel.
Blue Duck: “Mary Jane, this is Blue Duck” (the name of the vessel or MMSI being called may be said 2 or 3 times if conditions warrant)
Mary Jane: “Blue Duck, this is Mary Jane. Reply 68” (or some other proper working channel)
Blue Duck: “68” or “Roger”