Page 55 - Collision Avoidance Rules Guide

(d) In determining if risk of collision exists the following consid-
erations shall be among those taken into account:
(i) such risk shall be deemed to exist if the compass bearing
of an approaching vessel does not appreciably change;
(ii) such risk may sometimes exist even when an appreciable
bearing change is evident, particularly when approach-
ing a very large vessel or a tow or when approaching a
vessel at close range.

COMMENT:
Rule 7(d)(i) corresponds to the second paragraph of the Preliminary
to the Steering and Sailing Rules of the 1960 Regulations and
Rule 7(c) is similar to the first recommendation in the Annex to the
1960 Regulations.
As in the case of speed and look-out, the determining of risk of
collision has been given greater emphasis in the 1972 Regulations by
introducing a rule which deals specifically with this aspect of colli-
sion avoidance and which requires the proper use of radar in appro-
priate circumstances.
Risk of collision
Rules 12, 14, 15 and 18 require one vessel to keep out of the way of
another when risk of collision exists, When one of two vessels in
sight of one another is required to keep out of the way the other must
keep her course and speed (Rule 17). The question arises as to how
far apart the vessels must be before risk of collision should be con-
sidered to exist and the obligation to keep course and speed first
begins to apply to the privileged vessel.
The 1972 Conference rejected a proposed definition that ‘risk of
collision’ exists between vessels when their projected courses and
speeds place them at or near the same location simultaneously. Had
this definition been accepted a vessel detecting another at long range,
slowly approaching from the port side with little change of bearing,
would have been obliged to keep her course and speed for a long
period, possibly several hours.
In the Courts of the United Kingdom and other countries risk of
collision has not been held to apply at long distances when there is a
low speed of approach. As the above definition was not accepted the
previous Court interpretation should also apply to the 1972 Rules.

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