ANNEX III-Continued

2. Bell or gong

(a) Intensity of signal. A bell or gong, or other device having similar sound characteristics shall produce a sound pressure level of not less than 110 dB at a distance of 1 meter from it.

(b) Construction. Bells and gongs shall be made of corrosionresistant material and designed to give a clear tone. The diameter of the mouth of the bell shall be not less than 300 mm for vessels of 20 meters or more in length, and shall be not less than 200 mm for vessels of 12 meters or more but of less than 20 meters in length. Where practicable, a power-driven bell striker is recommended to ensure constant force but manual operation shall be possible. The mass of the striker shall be not less than 3 percent of the mass of the bell.

3. Approval

The construction of sound signal appliances, their performance and their installation on board the vessel shall be to the satisfaction of the appropriate authority of the State whose flag the vessel is entitled to fly.

ANNEX III-Continued

§ 86.15 Towing vessel whistles.

A power-driven vessel normally engaged in pushing ahead or towing alongside may, at all times, use a whistle whose characteristic falls within the limits prescribed by § 86.03 for the longest customary composite length of the vessel and its tow. Subpart B-Bell or gong

§ 86.21 Intensity of signal.

A bell or gong, or other device having similar sound characteristics shall produce a sound pressure level of not less than 110 dB at 1 meter.

§ 86.23 Construction.

Bells and gongs shall be made of corrosion-resistant material and designed to give a clear tone. The diameter of the mouth of the bell shall be not less than 300 mm for vessels of more than 20 meters in length, and shall be not less than 200 mm for vessels of 12 to 20 meters in length. The mass of the striker shall be not less than 3 percent of the mass of the bell. The striker shall be capable of manual operation.

NOTE: When practicable, a power-driven bell striker is recommended to ensure constant force.

Subpart C-Approval

§ 86.31 Approval. [Reserved]

ANNEX IV

Distress Signals

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-signalling 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;

(I) the radiotelegraph alarm signal;

(m) the radiotelephone alarm signal;

(n) signals transmitted by emergency position-indicating radio beacons.

ANNEX IV

Distress Signals

§ 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-signalling 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;

(1) The radiotelegraph alarm signal;

(m) The radiotelephone alarm signal;

(n) Signals transmitted by emergency position-indicating radio beacons;

(0) A high intensity white light flashing at regular intervals from 50 to 70 times per minute.

ANNEX IV-Continued

2. 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.

3. Attention is drawn to the relevant sections of the International Code of Signals, the Merchant Ship Search and Rescue Manual 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.