COLREG Rule 34 Warning Signals for Vessels In Sight Of Each Other

Extract from RULE 34 Manoeuvring and warming signals

(a) When vessels are in sight of one another, a power-driven vessel underway, when  maneuvering as authorized or required by these Rules, shall “1le that manoeuvre by the following signals on her whistle:

one short blast to mean “1 am altering my course to starboard”;

two short blasts to mean “l 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 ‘1 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“;

(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.

(7) If whistles are fitted on a vessel at a distance apart of more than 100 meters, one whistle only shall be used for giving maneuvering and warning signals.


Extract from Annex 1

Manoeuvrlng light

Not withstanding the provisions of paragraph 2 (f) of this Annex the maneuvering 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 meters vertically above the forward masthead light. provided that it shall be carried not less than 2 meters vertically above or below the after masthead light. On a vessel where only one masthead light is carried the maneuvering light, it fitted. shall be carried where it can best be seen. not less than 2 meters vertically apart from the masthead light.

COLREG Rule 34 Signals When In Sight In A Narrow Channel

Extract from RULE 34 Manoeuvring and warning signals
(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 ‘! intend to overtake you on your starboard side“;

two prolonged blasts followed by two short blasts to mean “1 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.

(f) If whistles are fitted on a vessel at a distance apart of more than 100 meters. one whistle only shall be used for giving manoeuvring and warning signals.

COLREG Rule 34 Signals To Attract Attention

Extract from RULE 36 Signals to attract attention

If necessary to attract the attention of another vessel any vessel may make light or sound signals that cannot be mistaken for any signal authorized elsewhere in these Rules. or may direct the beam at her searchlight in the direction or the danger. in such a way as not to embarrass any vessel. Any light to attract the attention of another vessel shall be such that it cannot be mistaken for any aid to navigation. For the purpose of this Rule the use at high intensity intermittent or revolving lights. such as strobe lights. shall be avowed.

COLREG Rule 31 Seaplanes And WIG Craft

Rule 31 Seaplanes

Where it is impracticable for a seaplane or a WIG craft to exhibit lights and shapes of the characteristics or in the positions prescribed in the Rules 0! this Part she shall exhibit lights and shapes as closely similar in characteristics and position as is possible.

COLREG Rule 29 & Rule 35 Pilot Vessels On Duty

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;

(ii) when underway, in addition. sidelights and a stern light;

(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.


Extract from Rule 35 Sound signals In restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(9) A vessel at anchor shall at intervals of not more than one minute ring the bell rapidly for about 5 seconds. In a vessel of 100 meters or more ln length the bell shall be sounded in the forepart of the vessel and immediately after the ringing of the bell the gong shall be sounded replay for about 5 seconds on the after part of the vessel. A vessel at anchor may in addition sound three blasts ln succession, namely one short, one prolonged and one short blast, to give Waring of her position and of the possibility of collusion to an approaching vessel.

COLREG Rule 27 Vessel Engaged In Mine Clearing Operations

Extract from RULE 27 - Vessels not under command or restricted ln their ability to manoeuvre

(f) A vessel engaged in minedearance 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 light: or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the foreyard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 metres of the mlneclearance vessel.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel
constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall. instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 27 Vessel Engaged In Dredging OR Underwater Operations

Extract from RULE 27 - Vessels not under command or restricted in their ability to manoeuvre

(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-paragraph (b) (i), (ii) and (iii) of this Rule and shall in addition, when an obstruction exists, exhibit:

(l) 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 meter in height. Measures shall be taken to ensure its all-round visibility.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession With an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel. a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 27 & Rule 35 Vessel Restricted, But Not Mine Clearin

Extract from Rule 27 - Vessel restricted in her ability to manoeuvre but not mine clearing

(b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in minedearance operations, shall exhibit:

(i) three all-round lights in a vertical line where they can best be seen. flue 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 stenlight, 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.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

COLREG Rule 27 & Rule 35 Vessel Not Under Command

Extract from Rule 27 - Vessels not under command or restricted in their ability no manoeuvre

(a) A vessel not under command shall exhibit:

(i) two ail-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 stern light.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day: or night, the signals prescribed in this Rule shall be used as follows:

a) A vessel not under command, a vessel restricted in her ability to manoeuvre. a vessel constrained by her draught. a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession. namely one prolonged followed by two short blasts.

COLREG Rule 26 & Rule 35 Fishing Vessel Engaged In Trawling

Extract from RULE 26 Fishing vessels

(a) A vessel engaged in fishing. whether underway or at anchor. shall exhibit only the lights and shapes prescribed in this Rule.

(b) A vessel when engaged in trawling. by which is meant the dragging through the water of a dredge net or other apparatus used as a fishing appliance. shall exhibit:

(i) Two all-round lights in a vertical line. the upper being green and the lower white. or a shape consisting of two cones with their apexes together in a vertical line one above the other;

(ii) A masthead light abaft of the higher than the all-hound green light; a vessel of less than 50 meters in length shall not be obliged to exhibit such a light but may do so;

(iii) When making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a stern light.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility. whether by day or night. the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to maneuver. a vessel
constrained by her draught. a sailing vessel. a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall. instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 26 & Rule 35 Fishing Vessel Engaged In Fishing Other Than Trawling

Extract from RULE 26 fishing vessels

(a) A vessel engaged in fishing, whether underway or at anchor, shall exhibit only the lights and shapes prescribed in this Rule.

(c) A vessel engaged in fishing. other than trawling. shall exhibit:

(i) two all-round lights in a vertical line, the upper being red and the lower white. or a shape consisting 0! two cones with apexes together in a vertical line one above the other;

(ii) when there is outlying gear extending more than 150 meters horizontally from the vessel. an all-round white light or a cone apex upwards in the direction of the gear;

(iii) when making way through the water. in addition to the lights prescribed in this paragraph. sidelights and a stern light.

(d) The additional signals described in Annex I! 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 of her length.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this

Rule shall be used as follows:

(a) A power-driven vessel making way through the wow shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel
constrained by her draught. a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall. instead of the signals prescribed in paragraphs (a) or (b)of this Rule, sound at intervals of not more than 2 minutes three blasts in succession. namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 25 And Rule 35 Sailing Vessels and Vessels Under Oars

RULE 25 Sailing vessels underway and vessels under oars

(a) A sailing vessel underway shall exhibit:

(i) sidelights;

(ii) a stern light.

(b) In a sailing vessel of less than 20 meters in length, the lights prescribed in paragraph (a) of this Rule, may be combined in one lantern carried at or near the top of the mast where they can best be seen

(c) A sailing vessel underway may, in addition to the lights prescribed in paragraph (a) of this rule, exhibit at or near the top of the mast. where they can best be seen, two all-round lights in a vertical line, the upper being red and the lower green, but these lights shall not be exhibited in communication with the combined lantern permitted by paragraph (b) of this Rule.

(d) (i) A sailing vessel of less than 7 meters in length shall, if practicable, exhibit the lights prescribed in paragraph (a) or (b) of this Rule, but if she does not, she shall have ready at hand an electric torch or lighted lantern shown a white light which shall be exhibited in sufficient time to prevent collision.

(ii) A vessel under oars may exhibit the lights prescribed in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric torch or lighted lantern showing a white light which shall be exhibited in sufficient time to prevent collision.

(e) A vessel proceeding under sail when also being propelled by machinery shall exhibit forward where it can best be seen a conical shape. apex downwards.


Extract from Rule 35 - Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals 0! not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(i) A vessel of less than 12 meters in length shall not be obliged to give the above-mentioned signals but, if she does not, shall maize some other efficient sound signal at intervals of not more than 2 minutes.

COLREG Rule 24 Vessel Puching Ahead Or Rowing Other Vessels Alongside

Extract from Rule 24 - Vessels Towing and Pushing

(a) A power-driven vessel when towing shall exhibit:

(i) instead of the light prescribed in Rule 23 (a) (i) or (a) (ll), two masthead lights in a vertical line. When the length of the tow, measuring from the stern of the towing vessel to the after end of the tow exceeds 200 metres, three such lights in a vertical line;

(ii) sidellghts;

(iii) a stemlight;

(iv) a towing light in a vertical line above the stern light;

(v) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen.

(b) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and exhibit the lights prescribed in Rule 23.

(c ) A power-driven vessel when pushing ahead or towing alongside, except in the case of a composite unit shall exhibit:

(0 instead of the light prescribed in Rule 23 (a) (i) or (a) (ii), two masthead lights in a vertical line;

(ii) sidelights;

(iii) a stem light.

Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(c) A vessel not under command. a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 24, Rule 27 And Rule 35 A Vessel Engaged In Towing

Extract from Rule 24 - Towing and pushing 

(a) A power-driven vessel when towing shall exhibit:

(i) instead of the light prescribed in Rule 23 (a) (i) or (a) (ii), two masthead lights in a vertical line. When the length of the tow, measuring from the stem of the towing vessel to the after end of the tow exceeds 200 metres. three such lights in a vertical line;

(ii) sidelights;

(iii) a stern light;

(iv) a towing light in a vertical line above the stern light;

(v) when the length oi‘ the tow exceeds 200 meters, a diamond shape where it can best be seen.

(d) A power driven vessel to which paragraphs (a) or (c ) of this Rule apply shall also comply with Rule

23 (a) (ii).

(i) Where from any sufficient cause it is impracticable for a vessel not normally engaged in towing operations to display the lights prescribed in paragraph (a) or (c) of this Rule, such vessel shall not be required to exhibit those lights when engaged in towing another vessel in distress or otherwise in need of assistance. All possible measures shall be taken to indicate the nature of the relationship between the towing vessel and the vessel being towed as authorized by Rule 36. in particular by illuminating the towline.

Extract from Rue 27 - Vessels not under command or restricted in their ability to manoeuvre

(b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in mineralogical operations. shall exhibit:

(i) three ail-round rights 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.

(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 (an), exhibit the lights or shapes prescribed in sub-paragraphs (b) (i) and (ii) of this Rule.

Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted Visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a sailing vessel. a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and shall give the signals prescribed in paragraphs (a) or (b) of this Rule

COLREG Rule 23 & Rule 35 Power Driven Vessels

Rule 23 - Power Driven vessel underway

(a) A power-driven vessel underway shall exhibit:

(i) a masthead light forward;

(ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 meters in length shall not be obliged to exhibit such light but may do so;

(iii) side Lights;

(iv) a side Lights;

(b) An air-cushion vessel when operating in the non-displacement mode shall, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit an all-round flashing yellow light.

(c) A WIG craft only when taking on, landing and in flight near the surface shall, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit a high intensity all-round flashing red light.

(d ) (i) A power-driven vessel of less than 12 meters in length may in lieu of the lights prescribed in paragraph (a) of this Rule exhibit an all round white light and sidelights;

(ii) a power-driven vessel of less than 7 meters in length whose maximum speed does not exceed 7 knots may in lieu of the lights prescribed in paragraph (a) of this Rule exhibit an all-round white light and shall, if practicable, also exhibit Sidelights;

(iii) the masthead light or all-round white light on a power-driven vessel of less than 12 meters in length may be displaced from the fore and at center line of the vessel if center line fitting is not practicable, powered that the sidelights are combined in one lantern which shall be carried on the fore and aft center line of the vessel or located as nearly as practicable in the same fore and aft line as the masthead light or the all-round white light.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule

shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the water shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.

COLREG Rule 24 & Rule 35 A Vessel Being Towed

Extract from Rule 24 e, f and g - Vessels Towing and Pushing

(e) A vessel or object being towed, other than those mentioned in paragraph (9) of this 3&4);

Rule, shall exhibit:

(i) sidelights;

(ii) a stern-light;

(iii) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen.

(f) Provided that any number of vessels being towed alongside or pushed in a group shall be lighted as one vessel,

(i) a vessel being pushed ahead, not being part of a composite unit, shall exhibit at the forward end, Sidelights;

(ii) a vessel being towed alongside shall exhibit a stern-light and at the forward end, sidelights.

(g) An inconspicuous, partly submerged vessel or object, or combination of such vessels or objects being towed, shall exhibit:

(i) if it is less than 25 meters in breadth, one all-round white light at or near the forward end and one at or near the after end except that dracones need not exhibit a light at or near the forward end.

(ii) if it is 25 meters or more in breadth, two additional all-round white lights at or near the extremities of its breadth;

(iii) if it exceeds 100 meters in length, additional all-round white lights between the lights prescribed in sub-paragraphs (i) and (ii) so that the distance between the lights shall not exceed 100 meters;

(iv) a diamond shape at or near the after most extremity of the last vessel or object being towed and if the length of the tow exceeds 200 meters an additional diamond shape where it can best be seen and located as far forward as is practicable.



Extract from Rule 24 h and l - Vessels Towing and Pushing

(h) Where from any sufficient cause it is impracticable for a vessel or object being towed to exhibit the lights or shapes prescribed in paragraph (e) or (g) of this Rule, all possible measures shall be taken to light the vessel or object towed or at least to indicate the presence of such vessel or object.

(i) Where from any sufficient cause it is impracticable for a vessel not normally engaged in towing operations to display the lights prescribed in paragraph (a) or (c) of this Rule, such vessel shall not be required to exhibit those lights when engaged in towing another vessel in distress or otherWise in need of assistance. All possible measures shall be taken to indicate the nature of the relationship between the towing vessel and the vessel being towed as authorized by Rule 36, in particular by illuminating the towline.


Extract from Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility. whether by day or night. the signals prescribed in this Rule shall be used as follows:

(e) A vessel towed or if more 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. When practicable. this signal shall be made immediately after the signal made by the towing vessel.

COLREG Rule 21 And Annex 1 Light And Shapes

Rule 21 Definitions of lights and shapes

(a) “Masthead light" means a white light placed over the fore and aft oenter line of the vessel showing an unbroken light over an arc oi the horizon of 225 degrees and so fixed as to show the light from right ahead to 22.5 degrees abai‘t the beam on either side of the vessel.

(b) ‘Sidelights" means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 meters in length the sidelights may be combined in one lantern carried on the fore and at oentefline of the vessel.

(c) ‘Stern light" means a white light placed as nearly as practicable at the stern showing an unbroken light over an arc of the horizon of 135 degrees and so fixed as to show the light 67.5 degrees from right al't on each side of the vessel.

(d) ‘Towing light’ means a yellow light having the same characteristics as the ‘stemming" defined in paragraph (c) of this Rule.

(e) “All round light“ means a light showing an unbroken light over an arc of the horizon of 360 degrees.

(f) “Flashing light" means a light flashing at regular intervals at a frequency of 120 flashes or more per minute.



Extracts from Annex 1 - Positioning and technical details of lights and shapes

1. Definition

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.

2. 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 followups:

(i) 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 6 meters. and, if the breadth of the vessel exceeds 6 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 12 meters;

(ii) when two masthead lights are carried the alter one shall be at least 4.5 meters vertically higher than the forward one.

(b) The vertical separation of 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 1,000 meters from the stem when viewed from sea level.

(g) The sidelights of a power-driven vessel shall be placed at a height above the hull not greater than three-quarters of that of the forward masthead light. They shall not be so low as to be interfered with by deck lights.



Extracts from Annex 1 - Positioning and technical details of lights and shapes (Continued)

6. Shapes

(a) Shapes shall be black and of the following sizes:

(l) a ball shall have a diameter of not less than 0.6 meter;

(ii) a cone shall have a base diameter of not less than 0.6 meter and a height equal to its diameter;

(iii) a cylinder shall have a diameter of at least 0.6 meter and a height of twice its diameter;

(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 meters.

COLREG Rule 20 And 32 Light And Shapes

Rule 20 - Application

(a) Rules in this Part shall be complied with in all weathers.

(b) The Rules concerning lights shall be complied with from sunset to sunrise, and during such times no other lights shall be exhibited, except such lights as cannot be mistaken for the lights specified in these Rules or do not impair their visibility or distinctive character, or interfere with the keeping of a proper lookout.

(c) The lights prescribed by these Rules shall, if carried. also be exhibited from sunrise to sunset in restricted visibility and may be exhibited in all other circumstances when it is deemed necessary.

(d) The Rules concerning shapes shall be complied with by day.

(e) The lights and shapes specified in these Rules shall comply with the provisions of Annex I to these Regulations.



Rule 32 - Sound signal definition

PART 0. SOUND AND LIGHT SIGNALS - RULE 32 Definitions

(a) The word “whistle” means any sound signaling appliance capable of producing the prescribed blasts and which compiles 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.

COLREG Rule 30 And Rule 35 A Vessel At Anchor

RULE 30 Anchored vessels and vessels aground

(a) A vessel at anchor shall exhibit where lt can best be seen:

(i) in the fore part. an all-round white light or one ball;

(ll) 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 meters in length may exhibit an all-round white light where it can be seen instead of the lights prescribed in paragraph (a) of this Rule.

(c) A vessel at anchor may, and a vessel 07 100 meters 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 ln a vertical line;

(ii) three balls in a vertical line.

(e) A vessel of less than 7 meters 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 meters in length when aground. shall not be required to exhibit the lights or shapes prescribed ln sub-paragraphs (d) (i) and (ll) of this Rule.


RULE 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night. the signals prescribed in this
Rule shall be used as follows:

(g) A vessel at anchor shall at intervals of not more than one minute ring the bell rapidly for about
5 seconds. In a vessel of 300 meters or more in length the bell shall be sounded in the forepart of the vessel and immediately after the ringing of the bell the gong shall be sounded rapidly for
about 5 seconds in the after part of the vessel. A vessel at anchor may in addition sound three blasts in succession. namely one short. one prolonged and one short blast. to give warning of her position and of the possibility of collision to an approaching vessel.

(h) A vessel aground shall give the bell signal and it required the gong signal prescribed ln paragraph (g) of this Rule and shall. in addition, give three separate and distinct stroked on the bell immediately before and after the rapid ringing of the bell. A vessel aground may in addition sound an appropriate whistle signal

COLREG Rule 30 A Vessel Aground

COLREG Rule 30 A Vessel Aground

Extract from 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 bail;

(ii) at or hear the stem and at a lower level than the light prescribed in sub-paragraph (i), an all-
round white light.

(b) A vessel ol less than 50 meters in length may exhibit an an-round white light where it can best
be seen instead of the lights prescribed in paragraph (a) of this Rule.

(c ) A vessel at anchor may, and a vessel of 100 meters 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;


RULE 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this
Rule shall be used as follows:

(9) A vessel at anchor shall at intervals of not more than one minute ring the bell rapidly for about
5 seconds. in a vessel of 100 meters or more in length the bell shale be sounded in the forepart of
the vessel and immediately alter the ringing of the bell the gong shall be sounded rapidly for
about 5 seconds in the after part of the vessel. A vessel at anchor may in addition sound three
blasts in succession, namely one short. one prolonged and one short blast. to give warning or her
position and of the possibility of collision to an approaching vessel.

(h) A vessel aground shall give the bell signal and it required the gong signal prescribed in
paragraph (9) of this Rule and shall, in addition, give three separate and distinct strokes on the
bell immediately before and after the rapid ringing of the bell. A vessel aground may in addition
sound an appropriate whistle signal

Series and Parallel Pumping Operations | What is Difference Between Series And Parallel Pump Operati

After successfully completing this lesson, You will be familiar with:
Series pumping Operations multistage
Parallel Pumping Operations

Positive Displacement Pumps

After successful completing this video lesson, you will be familiar with:

The operation of a reciprocating pumps.

Single and double acting reciprocating pumps.

The operation of several different rotary positive displacement pumps.

The relief valve is positive displacement pumps.

Rotodynamic Pumps | Rotodynamic Pump Working Animation

After successful completing this video lesson, you will be familiar with:

Different types of rotodynamic pumps.

The component parts of rotodynamic pumps.

Maintenance of rotodynamic pumps.

Operational Theory Pumps And Pumping Operation

After successful completing this video lesson you will be familiar with:

Head – Flow Curves

Power – Flow Curves

Net positive suction head

Cavitations; and how to prevent it

Pump Types And Operation

This video lesson is meant to serve as an introduction to the course.

Sailing with ECDIS

In this video you will learn how to use the ECDIS in Practices as an aid to navigation and how to use the functions and features in a safe and efficient way during a voyage.