Page 78 - Collision Avoidance Rules Guide

Rules 9(b), (c) and (d), lO(i) and (i) and 18(d). The following item of
Guidance was approved in 1982 by the Maritime Safety Committee;
‘When a vessel is required not to impede the passage of another
vessel, such a vessel shall so far as practicable navigate in such a way
as to avoid the development of risk of collision. If, however, a situa-
tion has developed so as to involve risk of collision, the relevant
Steering and Sailing Rules shall be complied with.’
The above Guidance is now superseded by the new Rule 8(f) which
establishes clearIy that the requirements of ‘not to impede’ are com-
plementary to other requirements of the Steering and Sailing Rules.
The requirement not to impede the passage or safe passage of
another vessel does not apply only to vessels in sight of each other
which are approaching in such a way that risk of collision is likely to
develop. The requirements of Rule 8(f) together with Rules 9(b), (c)
and (d), and lO(i) and (i) apply in both clear and restricted visibility.
For instance, a sailing vessel or small power-driven vessel which
becomes aware of the approach of a large power-driven vessel which
can safely navigate only within a narrow channel should take early
action to allow safe passage whether or not the other vessel is in sight.
When vessels are in sight of each other and are approaching in such
a way that risk of collision seems likely to develop the Rules of Part B
Section I1 become applicable. In such circumstances a vessel which is
required not to impede the passage of another vessel is not relieved of
that obligation if the other vessel will become the give-way vessel
when risk of collision exists. For instance, when a power-driven ves-
sel and a sailing vessel are approaching each other the power-driven
vessel is required by Rule 18(a) to keep out of the way when risk of
collision begins to apply, although she may be proceeding along a nar-
row channel or traffic lane, but this does not relieve the sailing vessel
of the obligation to take early action to allow sufficient sea room.
If one of two power-driven vessels, crossing so as to involve risk
of collision, is required not to impede the passage of the other vessel,
she must, in compliance with Rule 8(f), take early action to allow
sufficient sea room for the safe passage of the other vessel although
the other vessel may be required by Rule 15 to keep out of the way
(see page 101).
It will not always be possible, in the circumstances of the case, for
the vessel required not to impede to take early action to allow suffi-
cient sea room for the safe passage of the other vessel. For instance,
the day signal of a vessel constrained by her draught may not be
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