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) (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.
(d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.
Rule 17 lays down the principle that the ‘stand-on’ vessel’s part in collision avoidance, is to hold her course and speed so that the ‘give-way’ vessel can most easily gauge what degree of action is required.
Unfortunately, rather too many seamen have interpreted this rule to mean that they have absolute right of way, if approaching a vessel within the arc of its starboard navigation light. This is a major mistake, not least because ‘right of way’ is a purely fictitious notion anyway.
When reading this Rule, you should read it in the following manner:
Paragraph A (i) and (ii) followed by paragraph C then paragraph B and finally paragraph D.
This is because even if it is clear that collision is likely without immediate action and you are the ‘stand-on’ vessel, Rule 17 allows you to change course and/or speed if the other vessel is not taking action or can be seen not to be able to do all that is necessary. This also connects with Rule 2, which charges the vessel, owner, master and crew with taking every precaution necessary to stay safe.
No hard and fast guidelines can be given, but the same turn-to-starboard principle is best adhered to, if a course change is necessary. Remember, as far as the circumstances of the case admit, you should avoid an alteration to port for a vessel on your own port side, however tempting it might be to do so, as the result could be not only very embarrassing, but also potentially catastrophic.
However, when you are so close that action by the give way vessel alone will not result in an avoidance of the collision (i.e. you have hesitated for too long) Paragraph C says that you MUST now do something and that something could be an alteration to Port. If you ever find yourself in this situation, the circumstances of the case must be taken into account and this Rule is NOTsaying that in this situation you should go to Port.
The whole concept of maintaining course and speed applies only if a definite risk of collision occurs; and even then, only if no other factors apply. Taking the most controversial situation of one vessel approaching another vessel: if the OOW of the former vessel is keeping an effective watch, has a sense of self-preservation (Rule 2 again) and no incorrect conceptions about rights of way, he will alter course or change speed, whatever his position in relation to the ship long before an actual risk of collision can be deemed to exist. In other words, as soon as the OOW is not happy with what the other vessel is doing, he will himself start to do something about it.
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