Section 1 — Conduct of Vessels in any Condition of Visibility
Rule 8 : Action to avoid collision
(a) Any action to avoid collision shall be taken in accordance with the Rules of this Part and shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.
Qualification of the action: The action should be positive meaning that it should result in the reduction of the risk of collision, not aggravate it.
Should be made in ample time, implying that the assessment should be done in time and obviously that means that the situation should have been observed for quite some time and from a great distance – distance also correlates to the time interval between the time of observation, assessment and the time of the action. No daydreaming and then a wake up call to take action. Be alert.
Good seamanship, here a departure may be made from the rules, if for vessel very far on the horizon, it is seen that the vessel lies fine to starboard, also it is noted that for own vessel to alter course to increase the CPA would mean closing in on another danger, then – note she has to be at least 30 mins into the future, the own vessel may alter her course drastically to PORT for some time to increase the CPA. Although it is not recommended, this action may be necessary under these circumstances, rather than land up in a situation where you have the vessel on your starboard and you cannot alter course any further to starboard.
(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 shall be avoided.
The alteration of course always has to be large enough to be readily apparent to the other vessel. Small changes are not noticeable to other vessels since, the aspect during day time and the navigation light aspect at night may not appreciably differ from what it was before the small alteration of course, the other vessel then would be in doubt as to whether you have taken action or not – panic may set in.
Regarding speed change it is still harder to figure out when a vessel reduces from 14 knots to 13 knots, it is apparent if a vessel reduces from 14 knots to directly 10 knots.
(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.
Rather than speed alteration which being rather difficult to observe as such is difficult to assess the situation, and the apparent track remains the same. Thus a course alteration is much more effective in diffusing a dangerous situation and also is readily apparent to the other vessel – provided however that the alteration can be observed very easily by the other vessel.
The action should not be where the situation becomes worse, so it has to be done in time when the vessels are far away so that, the action taken can be further assessed, and if rectification is required may be done.
(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.
As explained above, all actions have to be assessed after taking them. All actions should diffuse the dangerous situation and the passing of the vessels should be with as wide a margin as possible under the conditions.
(e) If necessary to avoid collision or allow more time to asses the situation, a vessel may slacken her speed or take all way off by stopping or reversing her means of propulsion.
The above would happen in waters where ships are going in and out of the harbour limits. Since the ship may not have set a course also that the speed may not have to sufficient, a vessel may head in some different way, especially when transferring pilot etc, under these circumstances it is better to either stop and watch the situation as it develops or even if required to stop the vessel in her tracks – no movement, and then to assess the situation and then move cautiously.
- (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 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 obliged to comply with the rules of this part when the two vessels are approaching one another so as to involve risk of collision.
All of the above relate to vessels which have been required to keep out of the way of other vessels and not to hinder the passage of another vessel. These vessels should therefore take early action to keep clear, but if they fail then too they are obliged to follow the Rules to avoid a close quarter situation.
For the stand on vessel, it still has to follow the Rules irrespective of whether the other vessel takes action or not. Risk of collision at any costs has to be avoided.