Broadcast on VHF CH 70 by a person or vehicle in grave and imminent danger, requiring immediate assistance.

A Distress alert transmits the following information on VHF CH 70:

  • The vessel’s MMSI
  • The vessel’s position (either from an interfaced GPS or manually entered by the operator)
  • The UTC time indicating the time when the latest position was updated
  • The nature of Distress (it remains undesignated in case of Undesignated Distress Alert)
The vessel's position and UTC time indicating the time when the latest position was updated that are transmitted within a Distress Alert is very important information for the rescue operation. So, if VHF radio is not interfaced with GPS or automatic GPS entered position is not valid, position and time should be updated manually. The recommended minimum time period between updates is no more than 4 hours.

Practice on VHF radio simulator

  1. Press Menu softkey
  2. Press Posn softkey
  3. Press Posn softkey
  4. Enter Latitude and Longitude using keypad and N,S,E,W softkeys when available
  5. Press E key
  6. Enter UTC time (24-hour format) using keypad
  7. Press E key


Entering position and time manually

Normally broadcast to ALL STATIONS and received by all within VHF range of the station transmitting the alert.

Normally, it is expected that only a CRS will acknowledge the DSC Distress Alert by DSC and will act as the coordinator for the rescue, which would probably include other vessels in the vicinity.

Following on from the DSC Distress Alert, the station in distress will broadcast by voice on VHF CH 16 a Distress Message.


MAYDAY, MAYDAY, MAYDAY

THIS IS (Name of the vessel in distress spoken 3 times)

CALL SIGN and/or MMSI

MAYDAY

Name of the vessel, CALL SIGN and /or MMSI of the vessel in distress,

POSITION (Vessel's position) AT (Time of vessel's position in UTC)

(Type of accident)

IMMEDIATE ASSISTANCE REQUIRED

(Number of people onboard - Other information that could help SAR services such as weather conditions, activated EPIRB etc.)

OVER
Pattern of a Distress Call and Message

MAYDAY, MAYDAY, MAYDAY

THIS IS Sailboat Spinaker, Spinaker, Spinaker

MY CALL SIGN and/or MMSI IS.....

MAYDAY

THIS IS Spinaker, my call sign is Sierra 5 Lima 1 2 and my MMSI IS....

POSITION 450 36' North 0130 32' East AT 0545 UTC

The mast has broken and the engine is not strong enough to prevent us from grounding on a rocky shore

IMMEDIATE ASSISTANCE REQUIRED

5 persons on board and due to strong winds we can only remain on board for approximately two zero minutes

OVER
An example of a Distress Call and Message

Distress message must not begin from MAYDAY, MAYDAY, MAYDAY, if a Distress Call and Message were already sent. Distress message has to begin from MAYDAY in this situation.

There are three types of Distress Alert.

Undesignated Distress Alert

This is enabled by either pressing a single push button or pair of push buttons, normally covered by a protective flap, for a short period of time, usually 5 seconds.

To be used only when there is no time to compose an alert because:
  • the position and time that will be transmitted is not checked and corrected to be up to date,
  • the alert will not include information relating to the nature of distress (string "Undesignated" is sent).

Practice on VHF radio simulator

  1. The DISTRESS button is located under a protective cover that must be slid back before the button can be pressed.
  2. To send the call, press and hold the DISTRESS key for 5 seconds. A countdown to the transmission will be displayed. Release the key at any time during this countdown to abort the transmission.


Broadcast of an Undesignated Distress Alert. A subsequent DSC Acknowledgement is displayed from the CRS 002780200 (MRCC Koper , Slovenia)

Designated Distress Alert

This is enabled by programming the DSC Controller to include further information relating to the nature of distress and to update the time and position manually if necessary. The Designated Distress Alert is then broadcast by either pressing a single push button or pair of push buttons for 5 seconds after programming.

The following are internationally recognized Natures of Distress:
  • Fire/Explosion
  • Flooding
  • Collision
  • Grounding
  • Listing/Capsizing
  • Sinking
  • Disabled & Adrift
  • Abandoning
  • Man overboard
  • Undesignated (same as an unprepared Undesignated Distress Alert)

Practice on VHF radio simulator

  1. If the position and time displayed are not up to date, you should change them following the procedure already explained above. Then you can follow with setting up a Distress Alert
  2. The DISTRESS button is located under a protective cover that must be slid back before the button can be pressed
  3. Press the DISTRESS button to access the Distress Alert screen
  4. If position indicated on the display is not up to date:
    1. press a softkey indicating position
    1. Enter Latitude and Longitude using keypad and N,S,E,W softkeys when available
    2. Press E key
  5. If time indicated on the display is not up to date:
    1. Press a softkey indicating time
    2. Enter UTC time (24-hour format) using keypad
    3. Press E key
  6. Press the most lower softkey to scroll through natures of distress and select the most appropriate one
  7. To send the call, press and hold the DISTRESS key for 5 seconds. A countdown to the transmission will be displayed. Release the key at any time during this countdown to abort the transmission.


The setting up and broadcast of a Designated Distress Alert indicating collision as the nature of distress. A subsequent DSC Acknowledgement is displayed from the CRS 002780200 (MRCC Koper, Slovenia)

Distress Relay

This is only broadcast when a station learns that:
  • Another person/vehicle is in Distress and is unable to transmit the Distress Alert itself, for example red flares sighted at night or
  • The person/vehicle in Distress is beyond the VHF range of a CRS, for example in GMDSS Sea Area A2, A3 or A4, and you have acknowledged his DSC Distress Alert or subsequent Distress Call and Message by voice.

MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY

THIS IS (MMSI of the vessel), (Name of the vessel spoken 3 times), (Call sign of the vessel)

RECEIVED THE FOLLOWING MAYDAY FROM (MMSI of the vessel in distress), (Name of the vessel in distress), (Call sign of the vessel in distress)

MESSAGE BEGINS

(message received from vessel in distress or details of the distress)

MESSAGE ENDS

OVER
Pattern of a Distress Relay Call and Message

MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY

THIS IS Ferryboat Cathrine, Cathrine, Cathrine

MAYDAY

278054321, Spinaker, call sign Sierra 5 Lima 1 2

POSITION 450 36' North 0130 32' East AT 0545 UTC

The mast has broken and the engine is not strong enough to prevent us from grounding on a rocky shore

IMMEDIATE ASSISTANCE REQUIRED

5 persons on board and due to strong winds we can only remain on board for approximately two zero minutes

OVER
An example of a Distress Relay Call and Message

When a DSC Distress Alert is received by a CRS, there should be an immediate DSC acknowledgement from them. If the DSC Distress Alert goes unacknowledged, the DSC Controller will automatically repeat the broadcast at approximately 4 ½ minute intervals. A repeat broadcast can also be done manually by firstly cancelling the Distress Alert and re-programming the DSC Controller before once again by pressing the Distress button(s) for 5 seconds. When a DSC Distress Alert acknowledgement is broadcast, this automatically stops the repeat of the Alert. The information contained in the acknowledgement includes:
  • MMSI of the acknowledging CRS,
  • MMSI of the station in Distress.
Any subsequent RT Distress Call and Message broadcast on VHF CH 16 will be acknowledged by voice by both the CRS and vessels in the vicinity under the control of the CRS.

Reception of a Distress Alert

After the reception of a Distress Alert on VHF CH 70 a Distress Message on VHF CH 16 must be listened. Then wait for a CRS to acknowledge the call and for following voice communication on VHF CH 16. If your own vessel is able to assist, acknowledge the call by RT on VHF CH 16.

If a Distress Alert is not followed by an RT broadcast on VHF CH 16 or acknowledgment by any other station, acknowledge the call by RT on VHF CH 16 and proceed with voice communication on VHF CH 16 and try to notify the shore authorities by any means.

MAYDAY

(MMSI of the vessel in distress), (Name of the vessel in distress 3 times), (Call sign of the vessel in distress)

THIS IS (MMSI of the vessel), (Name of the vessel spoken 3 times), (Call sign of the vessel)

RECEIVED MAYDAY
Pattern of acknowledgment of a Distress Call on RT

Practice on VHF radio simulator

After the reception of a Distress Alert press softkey OK to cancel ringing and to clear the display. Press softkey arrow and arrow for more information about Distress Alert.


Reception of a Distress Alert

Control of communication on VHF CH 16

During distress silence on VHF CH 16 is automatically imposed. So, radio communication on VHF CH 16 should be controlled. This control is achieved by all stations voice broadcast on VHF CH 16 using some procedure words.

SEELONCE MAYDAY means that the VHF CH 16 may only be used by the vessel in distress and the responding authority (and any other vessels those ask for assistance in handling the emergency). It is used by the responding authority when another vessel is interfering with distress on VHF CH 16.

SEELONCE DISTRESS means that the VHF CH 16 may only be used by the vessel in distress and the responding authority (and any other vessels those ask for assistance in handling the emergency). It is used by any vessel when another vessel is interfering with distress on VHF CH 16.

PRUDONCE means that the VHF CH 16 may be used also for restricted radio working. It is used by the responding authority when initial distress problems have been dealt with and it is expected that distress won't be over soon.

SEELONCE FEENEE means that distress is over and normal radio working can be resumed on VHF CH 16. In most cases it is used by a CRS.

All messages to control radio communication on VHF CH 16 have the same pattern. Only different procedure words are used at different situations.


MAYDAY

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS (Name of the vessel or the responding authority spoken 3 times)

(Date and time in UTC)

(MMSI of the vessel in distress), (Name of the vessel in distress), (Call sign of the vessel in distress)

(procedure word)

OUT
Pattern of a Call and Messages to control radio communication on VHF CH 16

MAYDAY

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS RCC KOPER, RCC KOPER, RCC KOPER

21 November at 0615 UTC

278054321, Spinaker, call sign Sierra 5 Lima 1 2

SEELONCE FEENEE

OUT
An example of a Call and Messages to anounce that the distress is over

Cancelling False Alert

If a DSC Distress Alert is broadcast in error, the Alert must be stopped from repeating by either pressing a Cancel or Stop push button or by switching off the VHF DSC radio (it should be switched back on after a few seconds). An all stations voice broadcast should then be made on VHF CH 16, canceling the alert indicating that it was transmitted in error.

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS (MMSI of the vessel), (Name of the vessel spoken 3 times), (Call sign of the vessel)

POSITION (Vessel's position) AT (Time of vessel's position in UTC)

CANCEL MY DISTRESS ALERT OF (Original date and time of distress alert in UTC)

OVER
Pattern of a Call and Message to cancel a false Distress Alert

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS 278054321, Spinaker, Spinaker, Spinaker, call sign Sierra 5 Lima 1 2

POSITION 450 36' North 0130 32' East AT 0550 UTC

CANCEL MY DISTRESS ALERT OF 21 November at 0545 UTC

OVER
An example of a Call and Message to cancel a false Distress Alert

Viimeksi muutettu: maanantai 16. marraskuu 2020, 15.49