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

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Rule 8 -- Action to Avoid Collision


The Rules preceding Rule 8 address the correct identification of potential danger. Rule 8 begins a series of Rules that prescribe what to do once the risk of collision has been determined to exist. Rule 8 tells how the avoiding action must be executed, not which vessels are required to take the avoiding action. That is left to later Rules.

The International and the Inland Rule 8 are the same. Each applies to all vessels in all conditions of visibility. In good visibility, one vessel will usually have primary responsibility for taking avoiding action; in restricted visibility, vessels will share equally in that responsibility.


INTERNATIONAL

INLAND

(a) Any action taken to avoid collision shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.

(a) Any action taken to avoid collision shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.

 

Paragraph (a) is a general admonition to use care in avoiding collisions. Although the mandatory word "shall" appears, the paragraph also contains the escape clause "if the circumstances of the case admit." This means that in taking action you are not required to put yourself in a worse condition. You are not required to run aground (although in an extreme situation this may be the best course of action) or enter a collision situation with yet another vessel. Paragraph (a)'s admonition employs indefinite terms--actions are to be "positive," "made in ample time," and "with due regard to the observance of good seamanship."

"Positive" action is a significant change in vessel course or speed; paragraph (b) elaborates. "Ample time" and "with due regard" remind us to act early and do more than is absolutely necessary to avoid the collision, allowing a generous margin of safety both in time and in distance.

 

INTERNATIONAL

INLAND

(b) Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit, be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course and/or speed should be avoided.

(b) Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit, be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course and/or speed should be avoided.

 

Let the other vessel know what you are doing. Make it obvious by sight in good visibility and obvious on the radar screen in areas of restricted visibility. The give-way vessel in a crossing situation must alter course enough that the stand-on vessel will know it will pass astern. Give the proper maneuvering signals if operating under the International Rules. Call the other vessel by radiotelephone.

 

INTERNATIONAL

INLAND

(c) If there is sufficient sea room, alteration of course alone may be the most effective action to avoid a close-quarters situation provided that it is made in good time, is substantial and does not result in another close-quarters situation.

(c) If there is sufficient sea room, alteration of course alone may be the most effective action to avoid a close-quarters situation provided that it is made in good time, is substantial and does not result in another close-quarters situation.

 

Two variables can be altered to avoid collisions: course and speed. Large commercial vessels often find it easier to change course rather than to change speed, especially in open water when engine room personnel may not have taken the preliminary steps for speed changes. Hence, paragraph (c) allows for a course change alone, which can be made directly and immediately from the bridge. On smaller vessels, on other vessels with direct bridge-controlled engines, or especially on vessels with a controllable-pitch propeller, a speed change may be an equal or more effective action, even when there is ample sea room for a course change.

Paragraph (c) talks about avoiding a "close-quarters" situation. Does that imply a requirement to avoid a "close-quarters" situation? Close-quarters situations, of course, should be avoided where possible, but in rivers, harbors, and other inland waterways close-quarters situations are unavoidable.

How does "close-quarters" compare with the closest-point-of-approach distance that triggers risk of collision (see Rule 7 discussion), or with the "safe distance" of paragraph (d) of this Rule, or with the "well-clear" of Rule 16? As was mentioned in the discussion of Rule 7, the projected closest-point-of-approach between two vessels is one factor in assessing risk of collision. The distance between vessels for which "close quarters" would exist will always be less than the closest-point-of-approach distance that would trigger risk of collision; half the distance would almost certainly be "close quarters."

On the other hand, paragraph (d)'s "safe distance" and Rule 16's "well clear" mean much the same thing (the minimum passing distance permitted by the Rules), and both generally represent a smaller distance than "close-quarters." On inland waters especially, a give-way vessel passing well clear of (or at a safe distance from) another may, at the same time, be in a close-quarters/risk-of-collision situation with that vessel. Two vessels meeting in a narrow channel is an example. Extra caution makes such situations safe.

 

INTERNATIONAL

INLAND

(d) Action taken to avoid collision with another vessel shall be such as to result in passing at a safe distance. The effectiveness of the action shall be carefully checked until the other vessel is finally past and clear.

(d) Action taken to avoid collision with another vessel shall be such as to result in passing at a safe distance. The effectiveness of the action shall be carefully checked until the other vessel is finally past and clear.

 

Paragraph (d) requires that action taken result in passing at a safe distance. What distance is safe depends on the circumstances; suffice it to say that if you are obligated to take the action, the person on the other vessel should not feel compelled to act also to increase the distance still further.

Paragraph (d) also imposes the obligation to continue with the Rule 7 assessment of risk of collision until the other vessel is past and clear. You should especially consider the effects of normal maneuvers that the other vessel may begin while still in the vicinity. If in doubt, use your radiotelephone or your whistle signal.

 

INTERNATIONAL

INLAND

(e) If necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion.

(e) If necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion.

 

Paragraph (e) should be read in conjunction with paragraph (c). It directs vessels to slow down or stop to avoid a collision or to give more time in which to determine the best course of action. This prescription is only one of several on speed--see Rule 6 (Safe Speed), and Rule 19, paragraphs (b) and (e), relating to speed in restricted visibility.

The separation within Rule 8 of the requirements for course changes (paragraph (c)) and speed changes (paragraph (e)) should not be taken to mean that one method is preferred over the other. If action is required, the mariner must take effective and readily apparent action, whether it be a course change or a speed change or a combination of the two. A course change works better for meeting situations, whereas for vessels crossing at near-right angles, a speed change (perhaps in combination with a course change) often works better.

 

INTERNATIONAL

INLAND

(f)(i) A vessel which, by any of these Rules, is required not to impede the passage or safe passage of another vessel shall, when required by the circumstances of the case, take early action to allow sufficient sea room for the safe passage of the other vessel.

(ii) A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve the risk of collision and shall, when taking action, have full regard to the action which may be required by the Rules of this part.

(iii) A vessel the passage of which is not to be impeded remains fully obligated to comply with the Rules of this part when the two vessels are approaching one another so as to involve risk of collision.

(f)(i) A vessel which, by any of these Rules, is required not to impede the passage or safe passage of another vessel shall, when required by the circumstances of the case, take early action to allow sufficient sea room for the safe passage of the other vessel.

(ii) A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve the risk of collision and shall, when taking action, have full regard to the action which may be required by the Rules of this part.

(iii) A vessel the passage of which is not to be impeded remains fully obligated to comply with the Rules of this part when the two vessels are approaching one another so as to involve risk of collision.

 

International Rule 8(f) was added in 1989. (Parallel language was added to the Inland Rules in 1990.) This change puts to rest debates that had been ongoing for almost as long as the 72 COLREGS have existed. The "shall not impede" language comes into play in Rule 9 (narrow channels and narrow fairways), in International Rule 10 (traffic separation schemes), and in International Rule 18 (vessels constrained by draft). In each of these cases, usually larger vessels find themselves in situations where they are at a substantial maneuvering disadvantage with respect to smaller vessels in the area--smaller vessels that otherwise might be stand-on vessels.

The IMO Subcommittee on Safety of Navigation for a time had issued guidance on the meaning of the term "shall not impede." That guidance said that the "shall not impede" command meant to maneuver, when practicable, so far out of the way of the other vessel that risk of collision never develops, with the proviso that if risk of collision by some chance does develop, the more general Steering and Sailing Rules would take over (that is, the "shall not impede" rules would no longer be in effect).

The IMO subsequently decided that the guidance, if given at all, should be part of the Rules. During the course of the debate on the actual language, the delegates decided that the vessel that had been originally directed to not impede the other should retain that burden even after risk of collision arose. That does not mean, however, that the (usually larger) vessel that was not to be impeded continues to have the right of way. The new Rule provides that if the not-to-be-impeded vessel would be the give-way vessel under the general rules, it has the duty to stay out of the way of the impeding vessel after risk of collision arises. Under the new Rule, which changed the earlier official guidance in this respect, the impeding vessel also continues to have a duty to stay out of the way after risk of collision arises, and does not gain the stand-on status that the general rules might have given it. Both vessels would be obligated to stay out of the way.

If on the other hand, the not-to-be-impeded vessel would be the stand-on vessel under the general Steering and Sailing Rules, it would not lose that status. In that case, the impeding vessel would have a double duty to stay out of the way.

The "shall not impede" language in these cases creates an exception to the general rules, making them more practical. Vessels directed "not to impede" other vessels should take early action to keep clear by wide margins. The other vessel shouldn't become concerned enough to alter its course or speed, or otherwise feel obligated to act differently from the way it would if the would-be impeding vessel weren't there.

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