Stations not themselves in distress which learn that a ship, aircraft or other vehicle is in distress may transmit a distress relay message but only in the following circumstances.
- When the station in distress in not itself in position to transmit the distress message.
- When the master or other person responsible for the station not in distress consider the further help is required/ necessary.
- When, although not in position to render assistance, the station has received a distress message which is believed not to have been acknowledge.
Such message/ distress relay would normally be sent on 2182 kHz or channel 16 or any other R/T distress frequency.