Page 147 - Collision Avoidance Rules Guide

owners, but that in this case no steps had been taken to ensure that the
masters used their radar in a proper manner.

Ready for immediate maneuvre
A power-driven vessel is required to have her engines ready for
immediate manceuvre in restricted visibility, this will apply even in
the open ocean. For many vessels placing the engines on stand-by
involves some reduction of speed and loss of economy in fuel but this
must be accepted in the interests of safety. As it may take several
minutes to prepare the engines for immediate maneuvre the engi-
neers should be given as much notice as possible when it seems
likely that the visibility will become restricted.
Complying with the rules of Section I

Rule 19(c) emphasises the need to take the circumstances of
restricted visibility into account when complying with the Rules of
Section I of Part B. In addition to Rule 6 which relates to safe speed
this will apply particularly to Rules 5,7 and 8 dealing with look-out,
risk of collision and avoiding action. The Rules relating to navigation
in narrow channels and traffic separation schemes also apply in all
conditions of visibility.
In order to keep a good look-out in restricted visibility it will be
necessary to have a man posted on look-out duty by day as well as
by night and the radar should be kept under practically continuous
observation by a competent person. The use of radar will be essen-
tial, if fitted and operational, to determine whether risk of collision
exists with a vessel detected but not in sight in restricted visibility.
More substantial alterations of course will be necessary to avoid col-
lision with a vessel which is not in sight so that the manauvres will
be readily apparent on the other vessel’s radar screen, as required by
Rule 8(b). The effectiveness of avoiding action must be carefully
checked by radar observation if the other vessel is not in visual sight.

Detection by radar alone
Rule 19(d) applies to a vessel which detects another vessel, in
restricted visibility, by radar alone, Le., without sighting her visually
or hearing her fog signal. The Rules of Section I1 apply to vessels in
sight of one another and Rule 19(e) applies when a fog signal is
heard and there is possible risk of collision. If the vessel detected
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