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