Page 124 - Collision Avoidance Rules Guide

COMMENT:
Paragraphs (a)(i) and (b) are almost identical to Rule 21 of the 1960
Regulations. The remaining paragraphs are new and constitute one of
the most fundamental changes made by the 1972 Conference.

One of two vessels
A vessel is only required to maintain her course and speed in a two
vessel situation. In the unlikely event of one vessel finding herself on
a collision course with two other vessels at the same time, being in
one case the give-way vessel and in the other case the stand-on
vessel, she could not be expected to keep out of the way of one vessel
and maintain her course and speed for the other.

One vessel is to keep out of the way
Rules 12, 13, 15 and 18 require one of two vessels to keep out of the
way. The ‘give-way vessel’ is required to take early and substantial
action to keep well clear by Rule 16. Rule 17 lays down provisions
for the other vessel, referred to as the ‘stand-on vessel’.
Rule 17 does not apply if the two vessels concerned are not in
visual sight of each other, or if there is no risk of collision. This
means that, for instance, a power-driven vessel which detects
another vessel approaching from the port bow, or from more than
22.5” abaft the beam, and determines by radar that the bearing is not
changing, is not required to keep her course and speed if the vessel
cannot be sighted visually. There is also no obligation to keep
course and speed for a vessel sighted at long range, before risk of
collision begins to apply, even though the bearing may not be
appreciably changing.
A United Kingdom proposal to introduce a ‘Long Range Rule’,
which was intended to make it clear that disengagement was permit-
ted at long range, was not accepted by the Conference. The Chairman
stated that he had always assumed that a vessel had the right to take
action early in an encounter to disengage from what might become a
dangerous situation and this view was shared by other delegates.
Court decisions have also been made to this effect. The Rules in
Section I1 generally require one of two vessels to keep out of the way
when risk of collision exists and risk of collision has not been con-
sidered to apply at long ranges (see pages 36-7).

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