My seamanship question #1
 

On Tue, 12 Sep 2006 18:22:55 -0400, "Ellen MacArthur"
wrote:


"Capt. JG" wrote

| That's not worth an ASA point.


How come? You got it wrong too when in your other post you talked about one
of the boats being overtaken.

I see you people need a hint: Subtract the angles. Does the result fit the
definition of overtake?


White.

My seamanship question #1
 

Ellen MacArthur wrote:
"Capt. JG" wrote

| That's not worth an ASA point.


How come? You got it wrong too when in your other post you talked about one
of the boats being overtaken.

I see you people need a hint: Subtract the angles. Does the result fit the
definition of overtake?

Cheers,
Ellen

The vessel that is overtaking another vessel is the give-way vessel.

You said 180 was "overtaking" the 280 vessel.
End of story. Nothing else matters.

Joe

My seamanship question #1
 

Because the course difference is less then 67.5 degrees, the qualifies
as an overtaking situation. According to Rule 14,
"Notwithstanding anything contained in Rules 4 through 18, any
vessel overtaking any other shall keep out of the way of the vessel
being overtaken."

In other words, it doesn't matter that one or both are sailboats, or
small, the overtaking boat must stay clear.



Ellen MacArthur wrote:
A little sailboat with no motor is on the starboard tack catching up with another
little sailboat with no motor on the starboard tack. The one catching up is going
on a course of 180 degrees. The one getting caught is going 208 degrees.

Which one has to change course if it looks like they're going to hit each other?

Cheers,
Ellen

My seamanship question #1
 

Ellen MacArthur wrote:

How come? You got it wrong too when in your other post you
talked about one of the boats being overtaken.

I see you people need a hint: Subtract the angles. Does the
result fit the definition of overtake?

A vessel shall be deemed to be overtaking when coming up with another vessel
from a direction more than 22.5 degrees abaft her beam, ...

You have described the course that each vessel is on, the subtraction of one
from the other being 28 degrees - but this doesn't pertain to the direction
from the beam of the vessel being overtaken. You didn't define their
positions, only their courses, and stated that their courses look like they
will converge (which, for colreg purposes, is close enough to be considered
a potential collision situation).

So, we have a boat on 208deg, and another (catching up on the first) on
180deg, with a convergence point ahead if they maintain these courses.
Whether the catching boat is 22.5deg abaft of the other boat's beam is
unknown - they could be on a collision course, or not, depending on their
positions. See...

http://sports.webshots.com/photo/826...48327613VRqQxV

In the left-hand diagram, the green boat is overtaking the red one, but it
isn't in the right-hand diagram because it's ahead of the green one's
imaginary line representing 22.5deg abaft her beam. Until you define their
positions, it cannot be said for sure that the situation is an overtaking
one.

In lieu of that, I would say that the windward boat has to keep clear.


--
Capt Scumbalino

My seamanship question #1
 

Jeff wrote:
Because the course difference is less then 67.5 degrees, the qualifies
as an overtaking situation. According to Rule 14,
"Notwithstanding anything contained in Rules 4 through 18, any
vessel overtaking any other shall keep out of the way of the vessel
being overtaken."

In other words, it doesn't matter that one or both are sailboats, or
small, the overtaking boat must stay clear.



Ooops! That's Rule 13, of course!

And, since the question is a bit vague on the meaning of "it looks
like they're going to hit," and could be that the overtaken vessel may
be required take evasive action if a collision appears imminent.




Ellen MacArthur wrote:
A little sailboat with no motor is on the starboard tack catching
up with another
little sailboat with no motor on the starboard tack. The one catching
up is going
on a course of 180 degrees. The one getting caught is going 208 degrees.

Which one has to change course if it looks like they're going to
hit each other?

Cheers,
Ellen

My seamanship question #1
 

Jeff wrote:
Because the course difference is less then 67.5 degrees, the qualifies
as an overtaking situation. According to Rule 14,
"Notwithstanding anything contained in Rules 4 through 18, any
vessel overtaking any other shall keep out of the way of the vessel
being overtaken."

My understanding is that it isn't about differences in course, per-se, but
must also include the bearing from the vessel that is being caught, to the
vessel that is catching.


--
Capt Scumbalino

My seamanship question #1
 

On Wed, 13 Sep 2006 00:00:02 +0100, "Capt. Scumbalino"
wrote:

Ellen MacArthur wrote:

How come? You got it wrong too when in your other post you
talked about one of the boats being overtaken.

I see you people need a hint: Subtract the angles. Does the
result fit the definition of overtake?

A vessel shall be deemed to be overtaking when coming up with another vessel
from a direction more than 22.5 degrees abaft her beam, ...

You have described the course that each vessel is on, the subtraction of one
from the other being 28 degrees - but this doesn't pertain to the direction
from the beam of the vessel being overtaken. You didn't define their
positions, only their courses, and stated that their courses look like they
will converge (which, for colreg purposes, is close enough to be considered
a potential collision situation).

"The one catching up is going on a course of 180 degrees" If they are
to converge "the direction from the beam of the vessel being
overtaken" must be less than 28 degrees.

So, we have a boat on 208deg, and another (catching up on the first) on
180deg, with a convergence point ahead if they maintain these courses.
Whether the catching boat is 22.5deg abaft of the other boat's beam is
unknown - they could be on a collision course, or not, depending on their
positions. See...

http://sports.webshots.com/photo/826...48327613VRqQxV

In the left-hand diagram, the green boat is overtaking the red one, but it
isn't in the right-hand diagram because it's ahead of the green one's
imaginary line representing 22.5deg abaft her beam. Until you define their
positions, it cannot be said for sure that the situation is an overtaking
one.

In lieu of that, I would say that the windward boat has to keep clear.

My seamanship question #1
 

On Wed, 13 Sep 2006 00:12:02 +0100, Goofball_star_dot_etal
wrote:

On Wed, 13 Sep 2006 00:00:02 +0100, "Capt. Scumbalino"
wrote:

Ellen MacArthur wrote:

How come? You got it wrong too when in your other post you
talked about one of the boats being overtaken.

I see you people need a hint: Subtract the angles. Does the
result fit the definition of overtake?

A vessel shall be deemed to be overtaking when coming up with another vessel
from a direction more than 22.5 degrees abaft her beam, ...

You have described the course that each vessel is on, the subtraction of one
from the other being 28 degrees - but this doesn't pertain to the direction
from the beam of the vessel being overtaken. You didn't define their
positions, only their courses, and stated that their courses look like they
will converge (which, for colreg purposes, is close enough to be considered
a potential collision situation).

"The one catching up is going on a course of 180 degrees" If they are
to converge "the direction from the beam of the vessel being
overtaken" must be less than 28 degrees.

Oops! 90+ 14...


So, we have a boat on 208deg, and another (catching up on the first) on
180deg, with a convergence point ahead if they maintain these courses.
Whether the catching boat is 22.5deg abaft of the other boat's beam is
unknown - they could be on a collision course, or not, depending on their
positions. See...

http://sports.webshots.com/photo/826...48327613VRqQxV

In the left-hand diagram, the green boat is overtaking the red one, but it
isn't in the right-hand diagram because it's ahead of the green one's
imaginary line representing 22.5deg abaft her beam. Until you define their
positions, it cannot be said for sure that the situation is an overtaking
one.

In lieu of that, I would say that the windward boat has to keep clear.

My seamanship question #1
 

Capt. Scumbalino wrote:
Jeff wrote:
Because the course difference is less then 67.5 degrees, the qualifies
as an overtaking situation. According to Rule 14,
"Notwithstanding anything contained in Rules 4 through 18, any
vessel overtaking any other shall keep out of the way of the vessel
being overtaken."

My understanding is that it isn't about differences in course, per-se, but
must also include the bearing from the vessel that is being caught, to the
vessel that is catching.


Yes, you are correct. The method I used only works if they are going
approximately the same speed. However, without doing the calculation,
I would think that the overtaking vessel is going *much* faster if
this is technically a crossing situation. I'll have to work this out
on a calculator.

That brings up an interesting question: If a boat is going much faster
than another, so much so that its impossible for the slower to avoid
collision, which rule applies? Rule 17(b) clearly does, if action by
the giveway vessel alone is not enough to avoid collision. But also
Rule is important, because of the "special circumstances" and
"limitations of the vessels."

And if a collision occurred, how much liability gets assessed on the
giveway vessel?

This situation happens frequently when sport fishing boats are headed
out at 35 knots, crossing cruising boats powering at 6 knots.

My seamanship question #1
 

Capt. Scumbalino wrote:
Jeff wrote:
Because the course difference is less then 67.5 degrees, the qualifies
as an overtaking situation. According to Rule 14,
"Notwithstanding anything contained in Rules 4 through 18, any
vessel overtaking any other shall keep out of the way of the vessel
being overtaken."

My understanding is that it isn't about differences in course, per-se, but
must also include the bearing from the vessel that is being caught, to the
vessel that is catching.


--
Capt Scumbalino

Her wording has a very key phrase "Catching up with" this is an
overtaking situation not a crossing situation, therefore we know the
vessel is 22.5 degrees abaft the beam or she would have said they were
meeting or crossing IMO.

Joe