Distress signals
In plain language
Annex IV lists signals of distress: continuous fog-signal sounding, rockets or shells throwing red stars, SOS by any signalling method, red flares, orange smoke, slowly raising and lowering outstretched arms, and the square flag over or under a ball.
Full text of Rule 37
When a vessel is in distress and requires assistance she shall use or exhibit the signals described in Annex IV to these Regulations:
a gun or other explosive signal fired at intervals of about a minute;
a continuous sounding with any fog-signalling apparatus;
rockets or shells, throwing red stars fired one at a time at short intervals;
a signal made by radiotelegraphy or by any other signalling method consisting of the group ··· — — — ··· (SOS) in the Morse Code;
a signal sent by radiotelephony consisting of the spoken word “Mayday”;
the International Code Signal of distress indicated by NC;
a signal consisting of a square flag having above or below it a ball or anything resembling a ball;
flames on the vessel (as from a burning tar barrel, oil barrel, etc.);
a rocket parachute flare or a hand flare showing a red light;
a smoke signal giving off orange-coloured smoke;
slowly and repeatedly raising and lowering arms outstretched to each side;
a distress alert by means of digital selective calling (DSC) transmitted on: (a) VHF channel 70, or (b) MF/HF on the frequencies 2187.5 kHz, 8414.5 kHz, 4207.5 kHz, 6312 kHz, 12577 kHz or 16804.5 kHz;
a ship-to-shore distress alert transmitted by the ship’s INMARSAT or other mobile satellite service provider ship earth station;
signals transmitted by emergency position-indicating radio beacons;
approved signals transmitted by radiocommunication systems, including survival craft radar transponders.
Reproduced from the COLREGs 1972 (as amended) for study. Always verify against the official IMO publication.
Key points
- 1
Know at least six distress signals cold for any exam.
- 2
Flames on the vessel and red parachute flares are also distress signals.