symbols will be discussed in the section on
Aids to Navigation.
Risk of Collision (Rule 7a & d)
(a) Every vessel shall use all available
means appropriate to the prevailing
circumstances and conditions to determine
if risk of collision exists. If there
is any doubt such risk shall be deemed
to exist.
(d) In determining if risk of collision exists
the following considerations 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 approaching a very large
vessel or a tow or when approaching
a vessel at close range.
The Rules provide for action by the
STAND-ON and GIVE-WAY vessels for
most situations. A stand-on vessel, paying
close attention to a constant bearing
decreasing range (CBDR) situations, must
be alert and invoke the Rule 2b –take every
precaution required by ordinary practice
of seamen, including departure from the
rules to avoid immediate danger. A common
practice for avoidance turns if the
maneuvering room is available is turn to
starboard (right).
Action to Avoid Collision (Rule 8)
(a) Any action taken to avoid collision shall
be taken in accordance with Rules 4 -19
and shall if the circumstances of the
case admit, be positive, made in ample
time and with due regard to the observance
of good seamanship.
(b) Any alteration of course and/or speed
to avoid collision shall, if the circumstances
of the case admit, be large
enough to be readily apparent to
another vessel observing visually or
by radar; a succession of small alterations
of course and/or speed should be
avoided.
(c) If there is sufficient sea room, alteration
of course alone may be the most effective
action to avoid a close-quarters situation
provided that it is made in good
time, is substantial and does not result
in another close-quarters situation.
(d) Action taken to avoid collision with
another vessel shall be such as to result
in passing at a safe distance. The effectiveness
of the action shall be carefully
checked until the other vessel is finally
past and clear.
(e) If necessary to avoid collision or allow
more time to assess the situation, a vessel
may slacken her speed or take all
way off by stopping or reversing her
means of propulsion.
(f) (i) A vessel which, by any of these Rules,
is required not to impede the passage
or safe passage of another vessel
shall, when required by the circumstances
of the case, take early action
to allow sufficient sea room for the
safe passage of the other vessel.
(ii) A vessel required not to impede the
passage or safe passage of another
vessel is not relieved of this obligation
if approaching the other vessel
so as to involve risk of collision
and shall, when taking action, have
full regard to the action which may
be required by the Rules of Subpart
B (Rules 4-19).
(iii) A vessel, the passage of which is
not to be impeded remains fully
obliged to comply with the Rules
of Subpart B (Rules 4-19) when
the two vessels are approaching
one another so as to involve risk of
collision.
The Rules and Regulations include
actions to take when encountering another
vessel on the water. Some of the most com-
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