COLREGS - The Rules are divided into five parts A-E - General Rules (A), Steering and Sailing (B), Lights and Shapes (C), Sound and Light (D) and Exemptions (E).

SECTION II - CONDUCT OF VESSELS IN SIGHT OF ONE ANOTHER

RULE 11 - Application

Rules in this Section apply to vessels in sight of one another.

RULE 12 - Sailing vessels

(a) When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other as follows:

i. When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other;
ii. when both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward;
iii. if a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or on the starboard side, she shall keep out of the way of the other.

(b) For the purpose of this Rule the windward side shall be deemed to be the side opposite to that on which the mainsail is carried or, in the case of a square-rigged vessel, the side opposite to that on which the largest fore- and aft sail is carried.

RULE 13 - Overtaking

(a) Notwithstanding anything contained in the Rules of this Section any vessel overtaking any other shall keep out of the way of the vessel being overtaken.

(b) A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22,5 degrees abaft her beam, that is, in such a position with reference to the vessel she is overtaking, that at night she would be able to see only the stern light of that vessel but neither of her sidelights. 

(c) When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly.

(d) Any subsequent alteration of the bearing between the two vessels shall not make the overtaking vessel a crossing vessel within the meaning of these Rules or relieve her of the duty of keeping clear of the overtaken vessel until she is finally past and clear.

RULE 14 - Head-on situation

(a) When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision each shall alter her course to starboard so that each shall pass on the port side of the other

(b) Such a situation shall be deemed to exist when a vessel sees the other ahead or nearly ahead and by night she could see the masthead lights of the other in a line or nearly in a line and/or both sidelights and by day she observes the corresponding aspect of the other vessel

(c) When a vessel is in any doubt as to whether such a situation exists she shall assume that it does exist and act accordingly.

RULE 15 - Crossing situation

When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.

RULE 16 - Action by give-way vessel

Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.

RULE 17 - Action by stand-on vessel

(a) (i) Where one of two vessels is to keep out of the way the other shall keep her course and speed.

(ii) The latter vessel may however take action to avoid collision by her manoeuvre alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules.

(b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision.

(c) A power-driven vessel which takes action in a crossing situation in accordance with subparagraph (a)(2) of this Rule to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side.

(d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.

RULE 18 - Responsibilities between vessels

Except where Rules 9,10 and 13 otherwise require:

(a) A power-driven vessel underway shall keep out of the way of:
(i) a vessel not under command;
(ii) a vessel restricted in her ability to manoeuvre;
(iii) a vessel engaged in fishing;
(iv) a sailing vessel.

(b) A sailing vessel underway shall keep out of the way of:
(i) a vessel not under command;
(ii) a vessel restricted in her ability to manoeuvre;
(iii) a vessel engaged in fishing.

(c) A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:

(i) a vessel not under command;
(ii) a vessel restricted in her ability to manoeuvre.

(d) (i) Any vessel other than a vessel not under command or a vessel restricted in her ability to manoeuvre shall, if the circumstances of the case admit, avoid impeding the safe passage of a vessel constrained by her draught, exhibiting the signals in Rule 28.
(ii) A vessel constrained by her draught shall navigate with particular caution having full regard to her special condition.

(e) A seaplane on the water shall, in general, keep well clear of all vessels and avoid impeding their navigation. In circumstances, however, where risk of collision exists, she shall comply with the Rules of this Part.

(f) (i) A WIG craft shall, when taking off, landing and in flight near the surface, keep well clear of all other vessels and avoid impeding their navigation;
(ii) A WIG craft operating on the water surface shall comply with the Rules of this Part as a power-driven vessel.

Section III - Conduct of vessels in restricted visibility

Rule 19 - Conduct of vessels in restricted visibility

(a) This Rule applies to vessels not in sight of one another when navigating in or near an area of restricted visibility.

(b) Every vessel shall proceed at a safe speed adapted to the prevailing circumstances and conditions of restricted visibility. A power-driven vessel shall have her engines ready for immediate manoeuvre.

(c) Every vessel shall have due regard to the prevailing circumstances and conditions of restricted visibility when complying with the Rules of Section I of this Part.

(d) A vessel which detects by radar alone the presence of another vessel shall determine if a close-quarters situation is developing and/or risk of collision exists. If so, she shall take avoiding action in ample time, provided that when such action consists of an alteration of course, so far as possible the following shall be avoided.

(i) an alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken;
(ii) an alteration of course towards a vessel abeam or abaft the beam.

(e) Except where it has been determined that a risk of collision does not exist, every vessel which hears apparently forward of her beam the fog signal of another vessel, or which cannot avoid a close-quarters situation with another vessel forward of her beam, shall reduce her speed to the minimum at which she can be kept on her course. She shall if necessary take all her way off and in any event navigate with extreme caution until danger of collision is over.

Part A - General (Rules 1-3) & Part B- Steering and Sailing Section 1 - Conduct of vessels in any condition of visibility (Rules 4-10)

Rule 1 states that the rules apply to all vessels on the high seas and connected waters.
Rule 2 covers the responsibility of the master, owner and crew to comply with the rules.
Rule 3 includes definitions of applicable water craft (vessels).
Rule 4 says the section applies in any conditions of visibility.
Rule 5 every vessel shall at all times maintain a proper look-out by sight and hearing.
Rule 6 deals with safe speed.

Rule 7 risk assumptions shall not be made on scanty (radar) information.
Rule 8 covers action to be taken to avoid collision.
Rule 9 vessels proceeding along a narrow channel should keep to starboard.
Rule 10 deals with the behaviour of vessels in or near traffic separation schemes. 

Part C - LIGHTS & SHAPES (Rules 20-31)

Part D - SOUND AND LIGHT SIGNALS - DEFINITIONS (Rules 32-37)

Part E - EXEMPTIONS - Rule 38

Part F - Convention compliance verification provisions Rules 39 - 41

Annex I - Positioning and technical details of lights and shapes

Annex II - Additional signals for fishing vessels fishing in close proximity

Annex III - Technical details of sounds signal appliances

Annex IV - Distress signals indicating distress and need of assistance

International Maritime Organization (IMO)

4 Albert Embankment, London SE1 7SR

United Kingdom
+44 (0) 20 7735 7611

LINKS & REFERENCE

http://www.solarnavigator.net/boats/collision_at_sea_regulations_colregs.htm

https://www.bluebird-electric.net/COLREGS_International_Regulations_for_Preventing_Collisions_at_Sea_1972.htm

http://www.solarnavigator.net/boats/collision_at_sea_regulations_colregs.htm

https://www.bluebird-electric.net/COLREGS_International_Regulations_for_Preventing_Collisions_at_Sea_1972.htm