National United States Regulations 33 CFR PART 87—ANNEX IV: DISTRESS SIGNALS Title 33: Navigation and Navigable Waters PART 87—ANNEX IV: DISTRESS SIGNALS -------------------------------------------------------------------------------- Authority: 33 U.S.C. 2071; 49 CFR 1.46. § 87.1 Need of assistance. top 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. [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] § 87.3 Exclusive use. top The use or exhibition of any of the foregoing signals except for the purpose of indicating distress and need of assistance and the use of other signals which may be confused with any of the above signals is prohibited. [CGD 81–007, 47 FR 16174, Apr. 15, 1982] § 87.5 Supplemental signals. top Attention is drawn to the relevant sections of the International Code of Signals, the Merchant Ship Search and Rescue Manual, the International Telecommunication Union Radio Regulations and the following signals: (a) A piece of orange-colored canvas with either a black square and circle or other appropriate symbol (for identification from the air); (b) A dye marker. [CGD 81–007, 47 FR 16174, Apr. 15, 1982, as amended by CGD 89–024, 55 FR 3947, Feb. 6, 1990]