Page 132 - Collision Avoidance Rules Guide

vessel appears likely to strike the other abaft the beam, as shown in
the diagrams.
The above diagrams illustrate crossing cases in which the best
helm action for the stand-on vessel to take to avert collision would be
to turn to port.
When collision with another vessel is considered to be inevitable,
the foremost concern of the officer must be to manceuvre his ship so
as to reduce the effect of collision as much as possible. The conse-
quences are likely to be most serious if one vessel strikes the other at
a large angle near the mid length. The engines should be stopped, and
the helm should be used so as to achieve a glancing blow rather than
a direct impact. The damage would probably be the least serious if
the impact is taken forward of the collision bulkhead. When a vessel
is approaching on the port bow an alteration to starboard may well be
the worst possible action to take.

Obligation of the give-way vessel

A disadvantage of permitting the stand-on vessel to take action to
avoid collision by her manceuvre alone is that the give-way vessel
may be tempted to wait in the hope that the stand-on vessel will keep
out of the way. The purpose of Rule 17(d) is to emphasise that the
give-way vessel is not relieved of her obligation to take early and
substantial action to achieve a safe passing distance by the provisions
of Rule 17(a)(ii). A stand-on vessel is not permitted to manceuvre
until it becomes apparent that the give-way vessel is not taking
appropriate action in compliance with the Rules. The give-way vessel
should take positive action in ample time so that the stand-on vessel
can maintain her course and speed. If the stand-on vessel takes action
in accordance with Rule 17(a)(ii) the give-way vessel is not relieved
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