When there is risk of collision between a power driven vessel and a sailing vessel the power driven vessel shall keep out of the way except when?

Explanation of Rule 18 Responsibilities Between Vessels. Rule 18 follows Explanation

Vessels constrained by their draught.
Any vessel, except a vessel not under command or restricted in her ability to manoeuvre, must avoid impeding the safe passage of a vessel constrained by her draught and exhibiting the signals mentioned in Rule 28. The words ‘if the circumstances of the case admit’ are included in Rule 18(d) to take account of the fact that some vessels, particularly vessels engaged in fishing, may be unable to take effective avoiding action in sufficient time. A vessel required to avoid impeding the safe passage of a vessel constrained by her draught must, if the circumstances of the case admit, take early action to allow sufficient sea room for the safe passage of the other vessel. Rule 18(d)(ii) requires a vessel constrained by her draught to navigate with particular caution having full regard to her special condition.

Categories of vessels.
A vessel may only be justified in regarding herself as falling within a certain category of privileged vessels for the purpose of Rule 18 if she satisfies the conditions of the relevant definition of Rule 3 and is also showing the lights or shapes prescribed in the appropriate Rule of Part C. A vessel engaged in a towing operation is not privileged with respect to other vessels unless she is severely restricted in her ability to deviate from her course.

Action to be taken when Rule 18 applies A vessel required to keep out of the way by this Rule must take early and substantial action in accordance with Rule 16. The privileged vessel is required to keep her course and speed in accordance with Rule 17(a)(i), so far as she is able to do so. The give- way vessel must take into account the possibility that the nature of the work being carried out, or the special circumstances which apply, may make it impossible for the stand-on vessel to keep both course and speed.

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. A WIG craft, when taking off, landing and in flight near the surface, shall keep well clear of all other vessels and avoid impeding their navigation.

A WIG craft operating on the water surface shall comply with the Rules of this part as a power driven vessel.

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.

(d) A vessel engaged in fishing, when at anchor, and a vessel restricted in her ability to manoeuvre when carrying out her work at anchor, shall instead of the signals prescribed in paragraph (g) of this Rule sound the signal prescribed in paragraph (c) of this Rule.

(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.

(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.

(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 100 metres 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 if required the gong signal prescribed in paragraph

(g) 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.

(i) A vessel of 12 metres or more but less than 20 metres in length shall not be obliged to give the bell signals prescribed in paragraphs (g) and (h) of this Rule. However, if she does not, she shall make some other efficient sound signal at intervals of not more than 2 minutes.

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

(k) A pilot vessel when engaged on pilotage duty may in addition to the signals prescribed in paragraphs (a),(b) or (g) of this Rule sound an identity signal consisting of four short blasts.

Rule 11
Application

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

Rule 12
Sailing vessels

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:

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;
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;
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.

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

Notwithstanding anything contained in the Rules of part B, sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken.
A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5° 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 sternlight of that vessel but neither of her sidelights.
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.
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

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.
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.
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

1. Where one of two vessels is to keep out of the way the other shall keep her course and speed.
2. 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.
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.
A power-driven vessel which takes action in a crossing situation in accordance with subparagraph (a)(ii) 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.
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 power-driven vessel underway shall keep out of the way of:

a vessel not under command;
a vessel restricted in her ability to manoeuvre;
a vessel engaged in fishing;
a sailing vessel.

A sailing vessel underway shall keep out of the way of:

a vessel not under command;
a vessel restricted in her ability to manoeuvre;
a vessel engaged in fishing.

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

a vessel not under command;
a vessel restricted in her ability to manoeuvre.

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.
A vessel constrained by her draught shall navigate with particular caution having full regard to her special condition.

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.