Negative, former master.

It is true that the "shall not impede" rules are in affect in all conditions of
visibility, but as always, you've missed the important point. "Shall no impede" is NOT
the same as "give-way." There are similarities, to be sure, and in the extreme case they
are effectively the same. But the governing rules use very different language and mean
different things. In fact, Rule 8(f)iii stresses that the stand-on/give-way relationship
has not been altered - a "not to be impeded" vessel may still be the give-way vessel.

Further, its important to note that the "vessel not to be impeded" is not "stand-on" -
that is, it is not required to hold course and speed. In fact, it may well be required to
alter course. All that "shall not impede" requires is that the vessel is given sufficient
room for safe passage. The stand-on/give-way relationship implies that the stand-on
vessel should not have to alter course at all.

You have raised an interesting issue that the Narrow Channel and TSS Rules are in affect
in all conditions of visibility. It means that in heavy fog a sailboat should not cross a
channel if it is not able to determine if it is clear. This should be easy in a lightly
used channel, where you might only hear one fog signal, but would be impossible in a busy
channel without radar.


"Simple Simon" wrote in message
...
Very good dissertation. I'm glad you gave a good
explanation of shall not impede. One thing you did
not mention, however, is shall not impede applies
in all conditions of visibility. This means there
is give-way/stand-on vessel status in restricted
visibility.

S.Simon


"Jeff Morris" wrote in message
...
Well, (almost) no status is absolute because in (almost) any real life situation there
are
complexities not explicitly mentioned in the rules. For example, there is no explicit
mention of three vessel situations in the rules.

However, the phrase "shall not impede" is a bit more vague than most of the ColRegs.
Most
casual commentators, writing simplified rules for novices, will say that "shall not
impede" means the same as "keep out of the way off" that implies give-way status.
However, this is not the intent of the wording. "Shall not impede the safe passage"
means
that a vessel which might ordinarily have stand-on status, must leave the other vessel
a
reasonable amount of room to pass. The stand-on/give-way relationship still holds,
but
now the stand-on vessel may be required to alter course to accommodate the other
vessel.

The meaning of this, in practice, depends a lot on the actual situation. For
instance,
Rule 9(b) says that a vessel under 20 meters or a sailboat shall not impede a vessel
that
can only navigate within a channel - but it doesn't say anything about this vessel -
it
may be smaller and less restricted than the sailboat. If the vessel is actually more
maneuverable than the sailboat, it does not need a "protection" from 9(b). However,
if
the give-way vessel is an oil tanker, it may be on the only reasonable course, and any
alteration would be impeding its safe passage. Thus, the master of the sailboat has
to
appreciate the handling characteristics of the other vessel.

Since its rather unlikely that the novice small boat operator will understand the
needs of
the large ship, for these boats, interpreting "shall not impede" as meaning "give-way"
is
appropriate. However, it doesn't mean that a smaller power vessel becomes stand-on
WRT a
sailboat because its in a fairway. Thus, the status of vessels implied by the various
terms of Rules 9 and 10 are not as absolute as the "stand-on/give-way" status of Rule
18.

There has been much confusion over the use of "impede;" the IMO tried to clarify this
in
Rule 8 with some added clauses - their comments on this make it clear that "shall not
impede" is not as binding as "shall stay out of the way of," but the words of Rule 8
often
sound like gibberish. Fortunately, professional mariners seems to understand it.






"Jonathan Ganz" wrote in message
...
Hmmm... interesting point... I'm wondering when would be
a situation when that status isn't absolute... in the bay that is?

"Shen44" wrote in message
...
You tweaked a memory. In SF Bay, there's at least one area which is an RNA
and
small boats aren't allowed (around Pinole Shoal) and there may be others,
but
generally, I believe you'll find that everyone's working under the "shall
not
impede" rule. (I'd love to see some case history on this).
We are talking a legal point here that has room for confusion regarding
"stand
on" status ..... it's a part of the "Shall Not Impede" rule that many have
never liked.
I would like to say, you're correct, because the ship shall not be
impeded, he
has stand on status, but G that status is not absolute.

Shen