(iv) A diamond shape shall consist of two cones as defined in (ii) above having a common base.

(b) The vertical distance between shapes shall be at least 1.5 metre.

(c) In a vessel of less than 20 metres in length shapes of lesser dimensions but commensurate with the size of the vessel may be used and the distance apart may be correspondingly reduced.

7. Colour specification of lights. The chromaticity of all navigation lights shall conform to the following standards, which lie within the boundaries of the area of the diagram specified for each colour by the International Commission on Illumination (CIE).

The boundaries of the area for each colour are given by indicating the corner coordinates, which are as follows:

(i) White:

x=0.525, 0.525, 0.452, 0.310, 0.310, 0.443. y=0.382, 0.440, 0.440, 0.348, 0.283, 0.382. (ii) Green:

x=0.028, 0.009, 0.300, 0.203. y=0.385, 0.723, 0.511, 0.356. (iii) Red:

x=0.680, 0.660, 0.735, 0.721. y=0.320, 0.320, 0.265, 0.259. (iv) Yellow:

x=0.612, 0.618, 0.575, 0.575. y=0.382, 0.382, 0.425, 0.406.

8. Intensity of lights. (a) The minimum luminous intensity of lights shall be calculated by using the formula:

This shall not be achieved by a variable control of the luminous intensity.

9. Horizontal sectors. (a)(i) In the forward direction, sidelights as fitted on the vessel shall show the minimum required intensities. The intensities shall decrease to reach practical cut-off between 1 degree and 3 degrees outside the prescribed sectors.

(ii) For sternlights and masthead lights and at 22.5 degrees abaft the beam for sidelights, the minimum required intensities shall be maintained over the arc of the horizon up to 5 degrees within the limits of the sectors prescribed in Rule 21. From 5 degrees within the prescribed sectors the intensity may decrease by 50 per cent up to the prescribed limits; it shall decrease steadily to reach practical cut-off at not more than 5 degrees outside the prescribed sectors.

(b) All-round lights shall be so located as not to be obscured by masts, topmasts or structures within angular sectors of more than 6 degrees, except anchor lights prescribed in Rule 30, which need not be placed at an impracticable height above the hull.

10. Vertical sectors. (a) The vertical sectors of electric lights as fitted, with the exception of lights on sailing vessels underway shall ensure that:

(i) At least the required minimum intensity is maintained at all angles from 5 degrees above to 5 degrees below the horizontal;

(ii) At least 60 percent of the required minimum intensity is maintained from 7.5 degrees above to 7.5 degrees below the horizontal.

(b) In the case of sailing vessels underway the vertical sectors of electric lights as fitted shall ensure that:

(i) At least the required minimum intensity is maintained at all angles from 5 degrees above to 5 degrees below the horizontal;

(ii) At least 50 percent of the required minimum intensity is maintained from 25 degrees above to 25 degrees below the horizontal.

(c) In the case of lights other than electric these specifications shall be met as closely as possible.

11. Intensity of non-electric lights. Nonelectric lights shall so far as practicable comply with the minimum intensities, as specified in the Table given in Section 8 of this Annex.

12. Manoeuvring light. Notwithstanding the provisions of paragraph 2(f) of this Annex the manoeuvring light described in Rule 34(b) shall be placed in the same fore and aft vertical plane as the masthead light or lights and, where practicable, at a minimum height of 2 metres vertically above the forward masthead light, provided that it shall be carried not less than 2 metres vertically above or below the after masthead light. On a vessel where only one masthead

light is carried the manoeuvring light, if fitted, shall be carried where it can best be seen, not less than 2 metres vertically apart from the masthead light.

13. Approval. The construction of lights and shapes and the installation of lights 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 II

ADDITIONAL SIGNALS FOR FISHING VESSELS
FISHING IN CLOSE PROXIMITY

1. General. The lights mentioned herein shall, if exhibited in pursuance of Rule 26 (d), be placed where they can best be seen. They shall be at least 0.9 metre apart but at a lower level than lights prescribed in Rule 26 (b)(i) and (c)(i). The lights shall be visible all round the horizon at a distance of at least 1 mile but at a lesser distance than the lights prescribed by these Rules for fishing vessels.

2. Signals for Trawlers. (a) Vessels when engaged in trawling, whether using demersal or pelagic gear, may exhibit:

(i) When shooting their nets: two white lights in a vertical line;

(ii) When hauling their nets: one white light over one red light in a vertical line;

(iii) When the net has come fast upon an obstruction: two red lights in a vertical line. (b) Each vessel engaged in pair trawling may exhibit:

(i) By night, a searchlight directed forward and in the direction of the other vessel of the pair:

(ii) When shooting or hauling their nets or when their nets have come fast upon an obstruction, the lights prescribed in 2(a) above.

3. Signals for purse seiners. Vessels engaged in fishing with purse seine gear may exhibit two yellow lights in a vertical line. These lights shall flash alternately every second and with equal light and occultation duration. These lights may be exhibited only when the vessel is hampered by its fishing gear.

ANNEX III

TECHNICAL DETAILS OF SOUND SIGNAL
APPLIANCES

1. Whistles. (a) Frequencies and range of audibility.-The fundamental frequency of the signal shall lie within the range 70-700 Hz.

The range of audibility of the signal from a whistle shall be determined by those frequencies, which may include the fundamental and/or one or more higher frequencies, which lie within the range 180-700 Hz (+1 percent) and which provide the sound pressure levels specified in paragraph_1(c) below.

(b) Limits of fundamental frequencies. To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:

(i) 70-200 Hz, for a vessel 200 metres or more in length;

(ii) 130-350 Hz, for a vessel 75 metres but less than 200 metres in length;

(iii) 250-700 Hz, for a vessel less than 75 metres in length.

(c) Sound signal intensity and range of audibility. A whistle fitted in a vessel shall provide, in the direction of maximum intenIsity of the whistle and at a distance of 1 metre from it, a sound pressure level in at least one rd-octave band within the range of frequencies 180-700 Hz (±1 percent) of not less than the appropriate figure given in the table below.

The range of audibility in the table above is for information and is approximately the range at which a whistle may be heard on its forward axis with 90 percent probability in conditions of still air on board a vessel having average background noise level at the listening posts (taken to be 68 dB in the octave band centred on 250 Hz and 63dB in the octave band centred on 500 Hz).

In practice the range at which a whistle may be heard is extremely variable and depends critically on weather conditions; the values given can be regarded as typical but under conditions of strong wind or high ambient noise level at the listening post the range may be much reduced.

(d) Directional properties. The sound pressure level of a directional whistle shall be not more than 4dB below the prescribed sound pressure level on the axis at any direction in the horizontal plane within ±45 degrees of the axis. The sound pressure level at any other direction in the horizontal plane shall be not more than 10dB below the prescribed sound pressure level on the axis, so that the range in any direction will be at least half the range on the forward axis. The sound pressure level shall be measured in that rd-octave band which determines the audibility range.

(e) Positioning of whistles. When a directional whistle is to be used as the only whistle on a vessel, it shall be installed with its maximum intensity directed straight ahead.

A whistle shall be placed as high as practicable on a vessel, in order to reduce interception of the emitted sound by obstructions and also to minimize hearing damage risk to personnel. The sound pressure level of the vessel's own signal at listening posts shall not exceed 110 dB (A) and so far as practicable should not exceed 100 dB (A).

(f) Fitting of more than one whistle. If whistles are fitted at a distance apart of more than 100 metres, it shall be so arranged that they are not sounded simultaneously.

(g) Combined whistle systems. If due to the presence of obstructions the sound field of a single whistle or of one of the whistles referred to in paragraph 1 (f) above is likely to have a zone of greatly reduced signal level, it is recommended that a combined whistle system be fitted so as to overcome this reduction. For the purposes of the Rules a combined whistle system is to be regarded as a single whistle. The whistles of a !combined system shall be located at a distance apart of not more than 100 metres and arranged to be sounded simultaneously. The frequency of any one whistle shall differ from those of the others by at least 10Hz.

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 metre from it.

(b) 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 20 metres or more in Elength, and shall be not less than 200 mm $for vessels of 12 metres or more but of less

(d) A signal made by radiotelegraphy or by any other signalling 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 coloured 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) Approved signals transmitted by radiocommunication systems.

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-coloured canvas with either a black square and circle or other appropriate symbol (for identification from the air);

that are adopted by the Coast Guard for the guidance of the public.

[CGD 76-133, 42 FR 35792, July 11, 1977. Redesignated by CGD 81-017, 46 FR 28154, May 26, 1981]

§ 82.3 Pushing vessel and vessel being pushed: Composite unit.

Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven vessel and must exhibit the lights under

Rule 23. A "composite unit" is interpreted to be a pushing vessel that is rigidly connected by mechanical means to a vessel being pushed so they react to sea and swell as one vessel. "Mechanical means" does not include the following:

(a) Lines.

(b) Hawsers. (c) Wires.

(d) Chains.

[CGD 76-133, 42 FR 35792, July 11, 1977. Redesignated by CGD 81-017, 46 FR 28154, May 26, 1981]

(a) The term height above the hull means height above the uppermost continuous deck. This height shall be measured from the position vertically beneath the location of the light.

(b) The term practical cut-off means, for vessels 20 meters or more in length, 12.5 percent of the minimum luminous intensity (Table 84.15(b)) corresponding to the greatest range of visibility for which the requirements of Annex I are met.

(c) The term Rule or Rules means the Inland Navigation Rules contained in sec. 2 of the Inland Navigational Rules Act of 1980 (Pub. L. 96-591, 94 Stat. 3415, 33 U.S.C. 2001, December 24, 1980) as amended.

§ 84.03 Vertical positioning and spacing of lights.

(a) On a power-driven vessel of 20 meters or more in length the masthead lights shall be placed as follows: (1) The forward masthead light, or if only one masthead light is carried, then that light, at a height above the hull of not less than 5 meters, and, if the breadth of the vessel exceeds 5 meters, then at a height above the

hull not less than such breadth, so however that the light need not be placed at a greater height above the hull than 8 meters;

(2) When two masthead lights are carried the after one shall be at least 2 meters vertically higher than the forward one.

(b) The vertical separation of the masthead lights of power-driven vessels shall be such that in all normal conditions of trim the after light will be seen over and separate from the forward light at a distance of 1000 meters from the stem when viewed from water level.

(c) The masthead light of a powerdriven vessel of 12 meters but less than 20 meters in length shall be placed at a height above the gunwale of not less than 2.5 meters.

(d) The masthead light, or the allround light described in Rule 23(c), of a power-driven vessel of less than 12 meters in length shall be carried at least one meter higher than the sidelights.

(e) One of the two or three masthead lights prescribed for a powerdriven vessel when engaged in towing or pushing another vessel shall be placed in the same position as either the forward masthead light or the after masthead light, provided that the lowest after masthead light shall be at least 2 meters vertically higher than the highest forward masthead light.

(f)(1) The masthead light or lights prescribed in Rule 23(a) shall be so placed as to be above and clear of all other lights and obstructions except as described in paragraph (f)(2) of this section.

(2) When it is impracticable to carry the all-round lights prescribed in Rule. 27(b)(i) below the masthead lights, they may be carried above the after masthead light(s) or vertically in between the forward masthead light(s) and after masthead light(s), provided that in the latter case the requirement of § 84.05(d) shall be complied with.

(g) The sidelights of a power-driven vessel shall be placed at least one meter lower than the forward mast