87.1—Need of assistance.
The following signals, used or exhibited either together or separately, indicate distress and need of assistance:
(a)
A gun or other explosive signal fired at intervals of about a minute.
(b)
A continuous sounding with any fog-signaling apparatus;
(c)
Rockets or shells, throwing red stars fired one at a time at short intervals;
(d)
A signal made by radiotelegraphy or by any other signaling method consisting of the group . . . — — — . . . (SOS) in the Morse Code,
(e)
A signal sent by radiotelephony consisting of the spoken word “Mayday”;
(f)
The International Code Signal of distress indicated by N.C.
(g)
A signal consisting of a square flag having above or below it a ball or anything resembling a ball;
(h)
Flames on the vessel (as from a burning tar barrel, oil barrel, etc.);
(i)
A rocket parachute flare or a hand flare showing a red light;
(j)
A smoke signal giving off orange-colored smoke;
(k)
Slowly and repeatedly raising and lowering arms outstretched to each side;
(l)
The radiotelegraph alarm signal;
(m)
The radiotelephone alarm signal;
(n)
Signals transmitted by emergency position-indicating radio beacons;
(o)
Signals transmitted by radiocommunication systems, including survival craft radar transponders meeting the requirements of 47 CFR 80.1095.
(p)
A high intensity white light flashing at regular intervals from 50 to 70 times per minute.
Code of Federal Regulations
[CGD 81-007, 47 FR 16174, Apr. 15, 1982, as amended by CGD 89-024, 55 FR 3947, Feb. 6, 1990; CGD 94-011, 63 FR 5732, Feb. 4, 1998]