Handbook of the Nautical Rules of the Road by Llana & Wisneskey

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Rule 17 -- Action by Stand-on Vessel


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

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

 

Rule 17 assigns responsibilities to the vessel with the "right-of-way"--the stand-on vessel. The text of the Rule does not use the term "stand-on vessel" but instead describes it in paragraph (a) as the "other" vessel, that is, not the give-way vessel, not the vessel required to keep out of the way. When does this Rule apply? It applies only in situations covered by Rules 12, 13 ,15, and 18, which require one vessel to stay out of the way of another.

These four Rules apply only when the two vessels are in sight of one another and only when risk of collision exists. When three or more vessels approach with risk of collision it will likely will be impossible for all of them to act according to all of the Rules; one vessel may be the stand-on vessel with respect to a second and a give-way vessel with respect to a third. Rule 17 would require one action while Rule 16 would require a conflicting action. Such a situation is one of special circumstances and is governed by Rule 2.

Give-way vessels have one obligation--to stay out of the way of stand-on vessels. Stand-on vessels, however, have more complicated responsibilities, but their basic obligation is to hold their course and speed, or to "stand-on." Other actions are required or permitted depending on the circumstances.

Remember that give-way/stand-on situations do not begin until risk of collision (Rule 7) exists. You are free to maneuver before that risk arises no matter what your obligations would be later if you were to continue on your initial course.

Once risk of collision develops, however, paragraph (a)(i) requires the stand-on vessel to hold its course and speed. The purpose of this requirement is to enable the give-way vessel to predict the action of the stand-on vessel and so be able to stay out of its way. In some circumstances, the stand-on vessel's normal maneuver would be to slow down or turn (to pick up a pilot or enter a channel, for example) and such action may be expected of the stand-on vessel by those on the give-way vessel. In that case, the stand-on vessel is obligated to maneuver as expected, even though the action is something other than holding course and speed. Again, a radiotelephone confirmation of intentions is useful.


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(ii) The latter vessel may however take action to avoid collision by her maneuver 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.

(ii) The latter vessel may however take action to avoid collision by her maneuver 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.

 

The operator of a stand-on vessel that is on a collision course with another vessel expects the give-way vessel to take the prompt avoiding action required by the Rules. If after time has passed the give-way vessel persists in its impersonation of a stand-on vessel, it is reasonable to expect the stand-on vessel's operator to be somewhat concerned about the competence of the give-way vessel's crew.

As soon as it becomes apparent that the give-way vessel is not taking appropriate action, the stand-on vessel is free to act to avoid a collision. Rule 17(a)(ii) says that the stand-on vessel may maneuver at this stage, but it does not require the stand-on vessel to maneuver. The stand-on vessel may continue on for awhile before maneuvering. As soon as the stand-on vessel feels entitled to maneuver, however, it is required to immediately sound the doubt signal of five or more short blasts prescribed by Rule 34(d). Do not wait until danger is imminent. Do not wait until you are about to crash before sounding this signal!

The stand-on vessel may or may not choose to maneuver after giving the five-blast signal. If it does change direction and is operating under the International Rules, it must also then give the appropriate one- or two-blast signal to indicate that maneuver (see Rule 34(a)).

How long do you have to wait before it becomes "apparent" that the other vessel is not taking appropriate action? You may not take action until the give-way vessel has had time to assess the situation and to begin to take avoiding action. Precipitous action by the stand-on vessel may result on simultaneous action by both vessels, which can greatly increase the danger.

How close must you be to the other vessel before the stand-on vessel may maneuver? The same factors that determined the separation for risk of collision to exist apply here. A two-mile separation for ships crossing at sea would justify a stand-on vessel's maneuver. The particular circumstances in any given situation would, of course, determine the distance at which the stand-on vessel may maneuver to avoid the give-way vessel.

Rule 17(a)(ii) says that the stand-on vessel may act if the give-way vessel does not take "appropriate" action. Inappropriate action is no action at all or ineffective action.

If you are the operator of a stand-on vessel and decide to take action when the give-way vessel fails to do so, what action would be best? In a crossing situation (involving power-driven vessels), you normally would not want to slow down because that makes it more difficult for the give-way vessel to pass behind you. Remember that Rule 15 directs the give-way vessel to avoid crossing ahead of you. Rule 8 (Action to Avoid Collision) provides further guidance. For power-driven vessels, paragraph (c) of Rule 17 applies directly to this situation. It says don't turn left when the give-way vessel is on your port side. That means appropriate action is a right turn except when the give-way vessel is overtaking on your starboard side. For situations not involving two power-driven vessels, the appropriate action depends on the circumstances.


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(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.

(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.

 

You are on the stand-on vessel, and it becomes apparent that the give-way vessel on your port side is not taking appropriate action. You sound the five short blast signal, put your engines on stand-by, but continue holding your course and speed. Thirty seconds pass without any response. You again sound five short blasts. By this time you are much closer and through your binoculars observe a figure on an otherwise empty bridge jumping at what you assume to be the autopilot. The vessel's turn to the right is not fast enough to prevent a collision without your help, and you recall that Rule 17(b) now requires you to "take such action as will best aid to avoid collision." But what action? The right turn recommended for early stand-on avoiding action would at this point swing your stern into the oncoming bow of the give-way vessel. Aha! Hard left rudder. You pass safely.

Rule 17(b) describes the classic "in extremis" situation, one that every mariner wishes never to experience. Such a situation--one in which collision is imminent--is defined by the maneuverability of the give-way vessel alone. But what effect does the maneuverability of the stand-on vessel have? What will be the outcome if the stand-on vessel waits until the give-way vessel can't avoid the collision by itself?

If the two vessels are equally maneuverable, avoiding the collision will depend on the actions of both vessels. If the stand-on vessel is more maneuverable, then its quick action will probably prevent a collision. If, however, the stand-on vessel is less maneuverable than the give-way vessel, then the stand-on vessel can most likely do nothing to prevent the collision.

Therefore, if you are operating a stand-on vessel approaching a more maneuverable give-way vessel, it would behoove you not to wait until the Rules require you to maneuver to avoid collision. By that time it will probably be too late. If the give-way vessel isn't doing its job, take early advantage of Rule 17(a)(ii) and maneuver before the situation becomes more distressing.

You should remember that when the stand-on vessel is required to act to avoid collision (Rule 17(b)), it must take whatever action will best prevent or minimize collision damage. At that point, other requirements saying don't cross ahead, turn right, or whatever no longer apply. Do what has to be done.


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(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.

(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.

 

Turning away from the give-way vessel decreases the rate of approach and increases the time each vessel has to take further avoiding action. Turning toward the give-way vessel may well place the stand-on vessel in a much more dangerous situation if the give-way vessel has initiated a turn to starboard just before or simultaneously with the stand-on vessel's maneuver.


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

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

 

Finally, paragraph (d) of Rule 17 makes perfectly clear that the give-way vessel's responsibility to keep out of the way of the stand-on vessel is in no way diminished by the stand-on vessel's voluntary action under Rule 17(a)(ii) or by the stand-on vessel's required action under Rule 17(b). An operator of a give-way vessel is absolutely wrong in assuming he or she doesn't have to worry about staying out of the way (and passing at a safe distance) if the stand-on vessel takes avoiding action.

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