Page 126 - Collision Avoidance Rules Guide

vessel which in many cases was impossible to fulfil without making
collision inevitable. The moment for action was related to the other
vessel’s size and manoeuvring characteristics which are difficult to
assess, particularly at night. When the vessels are so close that colli-
sion cannot be avoided by the give-way vessel alone it should still be
possible for a relatively small and highly manceuvrable stand-on
vessel to avoid collision by her own action, but it can be shown that,
in the case of two merchant ships of equal size and speed in a cross-
ing situation with no change of compass bearing, continued failure to
keep out of the way by the give-way vessel would make collision
inevitable, irrespective of any action taken by the stand-on vessel.
An important new provision is made in Rule 17(a)(ii). This per-
mits a stand-on vessel to act at an earlier stage, to avoid collision by
her manceuvre alone, without having to justify such action as a nec-
essary departure from the Rules in order to avoid immediate danger.
A stand-on vessel is not specifically required to take action to
avoid collision as soon as it becomes apparent that the give-way ves-
sel is not taking appropriate action. She is permitted to keep her
course and speed until collision cannot be avoided by the give-way
vessel alone. However, the provision for permissive action places
greater emphasis on the obligation of the stand-on vessel to continu-
ously assess the situation when risk of collision exists to indicate any
doubt by use of the signals prescribed in Rule 34(d) and, subse-
quently, to take action before collision becomes inevitable. A stand-
on vessel which fails to take action in sufficient time to avoid
collision by her own manoeuvre is likely to be held at fault if a colli-
sion should occur. The difficulty of determining the precise moment
when action becomes compulsory is less likely to be accepted as a
valid excuse for waiting too long now that a stand-on vessel is
permitted to manceuvre at an earlier stage.

Earliest moment for permitted action
When risk of collision first begins to exist the stand-on vessel must
keep her course and speed. The give-way vessel is required to keep
out of the way in good time and to take substantial action which will
result in passing at a safe distance. The method of keeping out of the
way is not specified but in the case of two power-driven vessels
crossing the give-way vessel must avoid crossing ahead. A stand-on
vessel which takes avoiding action before it can reasonably be
107