Page 150 - Collision Avoidance Rules Guide

situation is developing. The Rules of Section I1 only apply to vessels
in sight of one another. However, when a vessel is approaching from
abaft the beam the relatively low rate of approach means that action
can be taken at shorter range and yet be made in ample time.

When action consists of an alteration of course

It was recommended in the Annex to the 1960 Rules that in order to
avoid a close quarters situation in restricted visibility an alteration to
starboard is generally preferable to an alteration to port, particularly
for vessels approaching apparently on opposite or nearly opposite
courses. This recommendation has subsequently been considered to
have been insufficient for the purpose of discouraging vessels from
turning to port in meeting or crossing situations so it was made
mandatory, by the 1972 Conference, to avoid altering course to port
for a vessel forward of the beam, except when overtaking. Rules
14, 15 and 17(c) virtually impose a similar restriction on power-
driven vessels in sight of one another which are meeting or crossing
so as to involve risk of collision.
An alteration of course to port to avoid a vessel being overtaken is
permitted as an alternative to an alteration to starboard, or change of
speed, whether the vessels are in sight or not. In the open sea a ves-
sel which is overtaking should preferably take action to avoid a close

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