(c) Every vessel shall have due regard to the
prevailing circumstances and conditions
of restricted visibility when complying
with Rules 4 -10.
(d) A vessel which detects by radar alone
the presence of another vessel shall
determine if a close-quarters situation
is developing and/or risk of collision
exists. If so, she shall take avoiding
action in ample time, provided that
when such action consists of an alteration
in course, so far as possible the
following shall be avoided:
Section 4: Navigation Rules 59
(i) An alteration of course to port for
a vessel forward of the beam, other
than for a vessel being overtaken;
(ii) An alteration of course toward a
vessel abeam or abaft the beam.
(e) Except where it has been determined
that a risk of collision does not exist,
every vessel that hears apparently forward
of her beam the fog signal of
another vessel, or that cannot avoid a
close-quarters situation with another
vessel forward of her beam, shall
reduce her speed to be the minimum
81
82
83
Table 4-3. Restricted Visibility Signals
Vessels at Anchor in Restricted Visibility
Length of Vessel Signal Required
Vessels under 20 meters A vessel less than 20 meters (65.6 feet) in length shall not
be obliged to give the bell signals prescribed for larger vessels.
However, if she does not, she shall make some other
efficient sound signal at intervals of not more than
2 minutes.
(65.6 feet)
Vessels of 20 meters A vessel at anchor shall at intervals not more than
or more one minute ring the bell rapidly for about 5 seconds. In
a vessel of 100 meters (328.1 feet) or more in length,
the bell shall be sounded in the forepart of the vessel and
immediately after the ringing of the bell the gong shall be
sounded rapidly for about 5 seconds in the afterpart of the
vessel.
All vessels A vessel at anchor may sound three blasts in succession,
namely one short, one prolonged, and one short blast, to
give warning of her position and of the possibility of collision
to an approaching vessel.
A vessel aground shall every minute sound three separate and distinct strokes on the bell
followed by rapid ringing of bell for 5 seconds and followed by three separate and distinct
strokes of the bell.
Vessels Underway in Restricted Visibility
Type of Vessel Number of Blasts
Powerboats making way 1 prolonged blast at intervals of not more than 2
minutes
Powerboats underway 2 prolonged blasts at intervals of not more than
but stopped 2 minutes
Sailing, fishing, trawling, 1 prolonged blast followed by 2 short blasts
or towing vessels restricted at intervals of not more than 2 minutes
in ablity to maneuver or not
under command