103Preventing Collisions at Sea White Red Green Red Red White Red Green A vessel engaged in fishing with nets or lines extending over the port side more than 150 m into the sea. Distance ‘a’ not less than 2 m and not more than 6 m. ‘a’ A vessel engaged in fishing, but not trawling, where the nets do not extend more than 150 m into the sea. All-round green above all-round white light Green Red Red Green Green End on Red Green Green Figure 5.16 Lights on trawler engaged in fishing at night. Additional masthead light for vessel over 50 m in length. Trawlers less than 50 m in length may also show this masthead light. Plan view, showing sidelights and stern lights Figure 5.17 Fishing vessel other than a trawler at night. Sources of reference: Rule 26 and Annex 1 Section 4a. A vessel engaged in fishing with nets or lines extending more than 150 metres into the sea, with starboard side exhibiting a single cone apex up in the direction of the extending gear. A vessel of unspecified length engaged in fishing. Figure 5.18 Fishing vessel’s day signals. Sources of reference: Rule 26 and Annex 1, Section 6. (iii) when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight. (d) The additional signals described in Annex II to these Regulations apply to a vessel engaged in fishing in close proximity to other vessels engaged in fishing. (e) A vessel when not engaged in fishing shall not exhibit the lights or shapes prescribed in this Rule, but only those prescribed for a vessel for her length. RULE 27 Vessels not under Command or Restricted in their Ability to Manoeuvre (a) A vessel not under command shall exhibit: (i) two all-round red lights in a vertical line where they can best be seen; (ii) two balls or similar shapes in a vertical line where they can best be seen; (iii) when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight. (b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in mine clearance operations, shall exhibit: (i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white; (ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond; (iii) when making way through the water, a masthead light or lights, sidelights and a sternlight, in addition to the lights prescribed in sub-paragraph (i); (iv) when at anchor, in addition to the lights or shapes prescribed in sub-paragraphs (i) and (ii), the light, lights or shape prescribed in Rule 30. 104 Seamanship Techniques (c) A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights or shapes prescribed in Rule 24 (a), exhibit the lights or shapes prescribed in sub-paragraphs (b)(i) and (ii) of this Rule. (d ) A vessel engaged in dredging or underwater operations, when restricted in her ability to manoeuvre, shall exhibit the lights and shapes prescribed in sub-paragraphs (b)(i), (ii) and (iii) of this Rule and shall in addition, when an obstruction exists, exhibit: (i) two all-round red lights or two balls in a vertical line to indicate the side on which the obstruction exists; (ii) two all-round green lights or two diamonds in a vertical line to indicate the side on which another vessel may pass; (iii) when at anchor, the lights or shapes prescribed in this paragraph instead of the lights or shape prescribed in Rule 30. (e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all lights and shapes prescribed in paragraph (d) of this Rule, the following shall be exhibited: (i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white; (ii) a rigid replica of the International Code flag ‘A’ not less than 1 metre in height. Measures shall be taken to ensure its all-round visibility. ( f ) A vessel engaged in mine clearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the lights or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 metres of the mine clearance vessel. (g) Vessels of less than 12 metres in length, except those engaged in diving operations, shall not be required to exhibit the lights and shapes prescribed in this Rule. (h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex IV to these Regulations. RULE 28 Vessels Constrained by their Draught A vessel constrained by her draught may, in addition to the lights prescribed for power-driven vessels in Rule 23, exhibit where they can best be seen three all- round red lights in a vertical line, or a cylinder. RULE 29 Pilot Vessels (a) A vessel engaged on pilotage duty shall exhibit: (i) at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red; 105Preventing Collisions at Sea Two all-round red lights, range 3 miles for a vessel of 50 m or more in length. 2 miles for other vessels. Vessel NUC but stopped on the water. The height of the lowest of the two red lights, ‘h’, on a vessel of 20 m or more in length must not be less than 4 m above hull (2 m above gunwale for vessels less than 20 m). Red Green The two all-round red lights when carried by a vessel over 20 m in length must be not less than 2 m apart. ‘h’ Vessel NUC under way and making way. Green Red Sidelights and stern lights shown when vessel is making way. Day signal, two black balls in a vertical line, shown where they can best be seen. Distance between two black balls at least 1.5 m Figure 5.19 Vessel not under command (NUC). Sources of reference: Rules 22, 27 and Annex 1, Section 6. (ii) when underway, in addition, sidelights and a sternlight; (iii) when at anchor, in addition to the lights prescribed in sub-paragraph (i), the light, lights or shape prescribed in Rule 30 for vessels at anchor. (b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length. RULE 30 Anchored Vessels and Vessels Aground (a) A vessel at anchor shall exhibit where it can best be seen: (i) in the fore part, an all-round white light or one ball; (ii) at or near the stern and at a lower level than the light prescribed in sub-paragraph (i), an all-round white light. (b) A vessel of less than 50 metres in length may exhibit an all-round white light where it can best be seen instead of the lights prescribed in paragraph (a) of this Rule. 106 Seamanship Techniques Red Green Vessel less than 50 m in length restricted in her ability to manoeuvre. Green Red, white, red, all-round lights shown where they can best be seen. Red Range 2 miles Head on Red Stern light 2 or 3 miles depending on size of vessel Viewed from astern Red Green Range of red, white. red, all-round lights 3 miles Day signal shown by any vessel restricted in her ability to manoeuvre. Red Green A vessel ‘probably’ over 50 m in length When not making way through water masthead, side, and sternlights not shown. Anchor ball shown in forepart of vessel and ball, diamond, ball shown where they may best be seen. Day signal for vessel of any length Red Red, white, red, all-round lights, and all-round anchor light, range 2 miles. Red Vessel whose length is less than 50 m. Red Red, white, red, all-round lights, range 3 miles. End on (not be confused with a vessel restricted in her ability to manoeuvre when under way and seen from astern). Anchor lights, range, 3 miles. Vessel of more than 50 m in length A vessel restricted in her ability to manoeuvre, when at anchor. Figure 5.20 Vessel restricted in her ability to manoeuvre. Sources of reference: Rules 3, 21, 22, 27 and Annex 1. Figure 5.21 Vessel restricted in her ability to manoeuvre, when at anchor. Sources of reference: Rules 22, 27, 30 and Annex 1. 107Preventing Collisions at Sea Two vessels in close proximity, day signal ball, diamond, ball, shown where they can best be seen. Transfer of fuel oil by pipeline. Regular practice with warships where more than one vessel may be replenished at the same time. Transfer of dry stores or personnel Red Green Red Red At night, all-round, red, white, red, lights, range 2 or 3 miles, depending on length of vessel under or over 50 m. Red Green The dredger will show masthead(s), side and stern lights as for a power driven vessel under way. In addition, she shall show the lights for a vessel restricted in her ability to manoeuvre, namely red, white, red, all-round lights, range 2 or 3 miles. Green Red Red Obstructed side This will be indicated by the exhibition of two all-round red lights, range 2 or 3 miles. Dredger under way and making way through the water. Red Green Clear side, free of obstructions Indicated by the exhibition of, two all-round green lights, range 2 or 3 miles. Dredger under way but stopped on the water. Obstruction may be in the form of a suction pipe or bucket/grab operation. Figure 5.22 Vessels engaged in replenishment at sea, restricted in their ability to manoeuvre. Sources of reference: Rules 3, 27, 36 and Annex 1. Figure 5.23 Vessel engaged in dredging or under water operations. Sources of reference: Rules 3, 22 and 27. 108 Seamanship Techniques Obstructed side Indicated by the exhibition of two black balls in a vertical line, not less than 1.5 m apart. A vessel engaged in dredging or underwater operations under way and making way, or stopped or at anchor – day signal as seen from right ahead or right astern. Indicated by the exhibition of two black diamond shapes, at least 1.5 m apart. Clear side free of obstructions In addition to the lights for a power-driven vessel or for a vessel at anchor, vessels engaged in mine clearance shall exhibit three all-round green lights, one at the foremast head and one at each yard. By day three black balls in place of the all-round green lights. 1000 m 1000 m 1000 m It is dangerous for another vessel to approach within the 1000 m limit. All other vessels should give a wide berth. 1000 m Day signal Green In addition to the lights for a power-driven vessel, three all-round red lights in a vertical line where they can best be seen. Figure 5.24 Vessel engaged in dredging operations by day. Sources of reference: Rules 3, 27 and Annex 1. Figure 5.25 Mine clearance operations. Sources of reference: Rules 3, 22, 27( f ), 30 and Annex 1. Figure 5.26 Vessel constrained by her draught. Sources of reference; Rules 3, 22, 28 and Annex 1 Section 6(a)iii and b(b). 109Preventing Collisions at Sea White over red all-round lights, range probably 2 miles. Red Green Green Red Pilot vessel is under way but not necessarily making way. Green Red Should the pilot vessel be over 50 m in length, then the range of the all-round lights would be 3 miles. Red At anchor at night Red By day Alternative flag signal ‘H’ in the International code of signals may be exhibited Figure 5.27 Pilot vessel engaged on pilotage duty. Sources of reference: Rules 21, 22, 29, 30, 35(i) and Annex 1. Single white all-round light, range 2 miles, shown where it can best be seen. Vessel less than 50 m in length at anchor at night. She may also illuminate her decks by use of working or other available lights. Not less than 6 m above hull All-round white lights, range 3 miles Forward anchor light, when two carried, not less than 4.5 m above after light. Vessel probably more than 50 m in length at anchor at night. (For a vessel less than 50 m in length the after anchor light is optional.) Diameter of the black ball not less than 0.6 m Figure 5.28 Vessel at anchor. Sources of reference: Rules 22, 30, and Annex 1, Sections 2(k) and 6(a). Day signal one black ball exhibited in the forepart of the vessel where it can best be seen. 110 Seamanship Techniques (c) A vessel at anchor may, and a vessel of 100 metres and more in length shall, also use the available working or equivalent lights to illuminate her decks. (d ) A vessel aground shall exhibit the lights prescribed in paragraph (a) or (b) of this Rule and in addition, where they can best be seen: (i) two all-round red lights in a vertical line; (ii) three balls in a vertical line. (e) A vessel of less than 7 metres in length, when at anchor, not in or near a narrow channel, fairway or anchorage, or where other vessels normally navigate, shall not be required to exhibit the lights or shape prescribed in paragraphs (a) and (b) of this Rule. ( f ) A vessel of less than 12 metres in length, when aground, shall not be required to exhibit the lights or shapes prescribed in sub-paragraphs (d)(i) and (ii) of this Rule. Figure 5.29 Vessel aground. Sources of reference: Rules 21, 22, 30, and Annex 1. Red In addition to the lights for a vessel at anchor two all-round red lights in a vertical line. Range of red all-round lights 2 miles Range of white all-round light 2 miles Vessel less than 50 m in length. End on Red Small vessel seen from the stern, where the single white light is obscured by superstructure. Not to be confused with a vessel NUC, stopped. Range of all-round red lights 3 miles Range of all-round white lights 3 miles Vessel 50 m or more in length 3 black balls in a vertical line Day signal For any vessel aground 111Preventing Collisions at Sea RULE 31 Seaplanes Where it is impracticable for a seaplane to exhibit lights and shapes of the characteristics or in the positions prescribed in the Rules of this Part she shall exhibit lights and shapes as closely similar in characteristics and position as is possible. PART D. SOUND AND LIGHT SIGNALS RULE 32 Definitions (a) The word ‘whistle’ means any sound signalling appliance capable of producing the prescribed blasts and which complies with the specifications in Annex III to these Regulations. (b) The term ‘short blast’ means a blast of about one second’s duration. (c) The term ‘prolonged blast’ means a blast of from four to six seconds’ duration. RULE 33 Equipment for Sound Signals (a) A vessel of 12 metres or more in length shall be provided with a whistle and a bell and a vessel of 100 metres or more in length shall, in addition, be provided with a gong, the tone and sound of which cannot be confused with that of the bell. The whistle, bell and gong shall comply with the specifications in Annex III to these Regulations. The bell or gong or both may be replaced by other equipment having the same respective sound characteristics, provided that manual sounding of the prescribed signals shall always be possible. (b) A vessel of less than 12 metres in length shall not be obliged to carry the sound signalling appliances prescribed in paragraph (a) of this Rule but if she does not, she shall be provided with some other means of making an efficient sound signal. RULE 34 Manoeuvring and Warning Signals (a) When vessels are in sight of one another, a power-driven vessel underway, when manoeuvring as authorized or required by these Rules, shall indicate that manoeuvre by the following signals on her whistle: — one short blast to mean ‘I am altering my course to starboard’; — two short blasts to mean ‘ I am altering my course to port’; — three short blasts to mean ‘I am operating astern propulsion’. (b) Any vessel may supplement the whistle signals prescribed in paragraph (a) of this Rule by light signals, repeated as appropriate, whilst the manoeuvre is being carried out: (i) these light signals shall have the following significance: — one flash to mean ‘I am altering my course to starboard’; — two flashes to mean ‘I am altering my course to port’; — three flashes to mean ‘I am operating astern propulsion’; 112 Seamanship Techniques All-round white light, range 5 miles for supplementing whistle signals. Fore and aft line Two optional positions for siting of manoeuvring light Not less than 2 m above aft masthead light Not less than 2 m below aft masthead light Where practical, a minimum of 2 m above forward masthead light Green This is an optional light, and therefore not necessarily carried by all vessels. When fitted, it should be in the same plane as the masthead lights and conform as near as is practicable to specifications in Annex 1. Figure 5.30 Manoeuvring light. Sources of reference: Rules 34, 36, and Annex 1, Section 12. (ii) the duration of each flash shall be about one second, the interval between flashes shall be about one second, and the interval between successive signals shall be not less than ten seconds; (iii) the light used for this signal shall, if fitted, be an all-round white light, visible at a minimum range of 5 miles, and shall comply with the provisions of Annex I to these Regulations. (c) When in sight of one another in a narrow channel or fairway: (i) a vessel intending to overtake another shall in compliance with Rule 9(e)(i) indicate her intention by the following signals on her whistle: — two prolonged blasts followed by one short blast to mean ‘I intend to overtake you on your starboard side’; — two prolonged blasts followed by two short blasts to mean ‘I intend to overtake you on your port side’; (ii) the vessel about to be overtaken when acting in accordance with Rule 9(e)(i) shall indicate her agreement by the following signal on her whistle: — one prolonged, one short, one prolonged and one short blast, in that order. (d ) When vessels in sight of one another are approaching each other and from any cause either vessel fails to understand the intentions or actions of the other, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle. Such signal may be supplemented by a light signal of at least five short and rapid flashes. (e) A vessel nearing a bend or an area of a channel or fairway where other vessels may be obscured by an intervening obstruction shall sound one prolonged blast. Such signal shall be answered with a prolonged blast by any approaching vessel that may be within hearing around the bend or behind the intervening obstruction. ( f ) If whistles are fitted on a vessel at a distance apart of more than 100 metres, one whistle only shall be used for giving manoeuvring and warning signals. [...]... (iii) Red x y (iv) Yellow x y 0. 525 0.3 82 0. 525 0.440 0.4 52 0.440 0.310 0.348 0. 028 0.385 0.009 0. 723 0.300 0. 511 0 .20 3 0.356 0.680 0. 320 0.660 0. 320 0.735 0 .26 5 0. 721 0 .25 9 0.6 12 0.3 82 0.618 0.3 82 0.575 0. 425 0.310 0 .28 3 0.443 0.3 82 0.575 0.406 8 Intensity of lights (a) The minimum luminous intensity of lights shall be calculated by using the formula: I = 3.43 × 106 × T × D2 × K–D where I is luminous intensity... Special signals for purse seiners Sources of reference: Annex II and M 587, July 1970  122 Seamanship Techniques Length of vessel in metres 20 0 or more 75 but less than 20 0 20 but less than 75 Less than 20 1/3rd-octave band level at 1 metre in dB referred to 2 × 10–5 N/m2 Audibility range in nautical miles 143 138 130 120 2 1.5 1 0.5 The range of audibility in the table above is for information and is approximately... viewed from sea level (c) The masthead light of a power-driven vessel of 12 metres but less than 20 metres in length shall be placed at a height above the gunwale of not less than 2. 5 metres 115 116 Seamanship Techniques (d ) A power-driven vessel of less than 12 metres in length may carry the uppermost light at a height of less than 2. 5 metres above the gunwale When however a masthead light is carried... variable): 1 2 3 4 5 6 7 8 9 10 11 12 Height from sea bed to top of drilling derrick 690 ft (21 0 m) Height of top deck from sea bed 550 ft (167.6 m) Drilling radius covered from platform 9000 ft (27 43 m) Directional drilling, maximum deviation, 55° Nominal production per day – 125 ,000 barrels (variable) Total number of piles – 44 Number of piles in each leg – 11 Maximum depth of piles 25 0 ft (76 .2 m) Diameter... diameter Cone Diamond 2 x diameter Figure 5. 32 Cylinder 2 x diameter Not less than 0.6 m Shape specifications for vessel of 20 m or more in length All shapes are black In a vessel less than 20 m in length the shapes’ dimensions may be less than those given, but must be commensurate with the size of the vessel Distance between shapes may also be correspondingly reduced 118 Seamanship Techniques 6 Shapes... 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 Non-electric lights shall so far as practicable comply with the minimum intensities, as specified in the table given in Section 8 of this Annex 119 120 Seamanship Techniques 12 Manoeuvring light... are exercising in this area’ (Mariners Handbook) A vessel is engaged in fishing with nets and lines extending across the bow of your vessel (not trawling) You are restricted in your 131 1 32 Seamanship Techniques 21 22 movements by the proximity of land masses and shoals and you are forced to cross over the fishing nets What precautions would you expect to take? (a) Stop the vessel’s propeller when passing... mean sea level 77 ft (23 .5 m) Number of deck levels – 3 Deck dimensions 175 ft (53.3 m) × 170 ft (51.8 m) Accommodation on each platform will vary, but 20 0 men at any one time is not uncommon Lifesaving appliances generally include either Survival Systems International capsules or totally enclosed lifeboats together with life rafts 19 Operational offshore installation  128 Seamanship Techniques Secondary... flashing 2 + 1 (group flashing) Figure 5.46 Preferred channel marks, System ‘A’ 134 Seamanship Techniques Green Figure 5.47 Buoys, System ‘B’ Lights when fitted, green for port and red for starboard, have any rhythm other than the composite group (2 + 1) as used for preferred channel marks Red Green Red Green Preferred channel to starboard, green with red stripe, and green light flashing 2 + 1 (group... than one vessel is towed the last vessel of the tow, if manned, shall at intervals of not more than 2 minutes sound four blasts in succession, namely one prolonged followed by three short blasts Two vessels approaching a bend or an obstruction which obscures the vision of each from the other 114 Seamanship Techniques (f ) (g) (h) (i ) ( j) When practicable, this signal shall be made immediately after . 0. 525 0. 525 0.4 52 0.310 0.310 0.443 y 0.3 82 0.440 0.440 0.348 0 .28 3 0.3 82 (ii) Green x 0. 028 0.009 0.300 0 .20 3 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 .26 5. as above 122 Seamanship Techniques Length of vessel in metres 1/3rd-octave band level at Audibility range in 1 metre in dB referred to nautical miles 2 × 10 –5 N/m 2 200 or more 143 2 75 but. manoeuvre. Sources of reference: Rules 3, 27 , 36 and Annex 1. Figure 5 .23 Vessel engaged in dredging or under water operations. Sources of reference: Rules 3, 22 and 27 . 108 Seamanship Techniques Obstructed side Indicated