Seamanship Question #32
 

Joe wrote:

I was busy givin the lubber more rope to hang herself.

If you do not give me a full point I will file a protest... and
request the ASA points commitee to rule on this matter.

You should know by now that Bart's points are hard to win. You were lucky
not to taste the cat'o'nine for such a half-assed answer. You'll be luckier
still not to have the half point deducted for making waves with the
committee. Still, the lubber could have been in danger of getting keelhauled
for that rule of 3rds nonsense...


--
Capt Scumbalino

Seamanship Question #32
 

Joe wrote:
Bart Senior wrote:
I'll give you 1/2 a point, because you did not explain how
it worked.


I was busy givin the lubber more rope to hang herself.

If you do not give me a full point I will file a protest... and request
the ASA points commitee to rule on this matter.

Joe


"Joe" wrote in message
oups.com...
Bart Senior wrote:
The point I wanted to make you covered. 1 point to Capt
Scumbalino.
NO FAIR! I said rules of 12 first, gimme my point you Scurvey dog!

Joe

We gonna have a duel at dusk?

Seamanship Question #32
 

Jeff wrote:

While the Rule of 12ths is a very handy tool for estimating the tide
height at any point in the cycle, I would be very careful of using to
extrapolate total range from one hour's observation. For instance, if
your observation were off by one inch, then you might mis-estimate the
full range by a foot.

I'd agree with that. The way I read the question, I took it that the only
information available was what could be observed over the next hour, hence
the extrapolation. I'd much rather know the tidal range and work from big to
small. :-)


--
Capt Scumbalino

Seamanship Question #32
 

Everybody should read your post...

Very erudite of you, Capt. And you didn't lose your temper. And you didn't call
me names. Your a good example for how newsgroup discussion should be done.

Cheers,
Ellen



"Capt. Scumbalino" wrote in message ...
| Ellen MacArthur wrote:
|
| Thanks for the explanation. So what's the difference between the
| rule of 12ths and the rule of thirds. In the rule of thirds the first
| two hours it goes down 1/4 which is the same as your 3/12th. The
| second two hours it goes down 1/2 which is the same as your 6/12th
| and the third two hours it goes down 1/4 which is the same as your
| 3/12th. See I got it right in spite of myself.
|
| It's based on the pretty-much universal fact that the time for the tide to
| change from high to low water, and vice-versa, is pretty close to six hours.
| Since we humans deal with time in chunks of one hour, the question we ask
| is: "how much does the tide change in one hour?". Since the smallest
| fraction is one twelfth, just before and just after slack water, it's
| natural to refer to the tidal change during other hours in terms of the same
| denominator. One twelfth in the first hour leads us to express the change
| during the second as two twelfths, etc.
|
| Also, the larger the time slot, the greater the granularity. Imagine you're
| waiting for the tide to rise enough to clear a sandbar. The rule of thirds
| would have you waiting in chunks of two hours before you sail. The rule of
| 12ths would keep you at anchor for chunks of one hour. Of course, plot the
| heights on a graph over time, and you can pinpoint your departure time
| (rather, the time at which you can safely cross the sandbar) much more
| finely.
|
| Whilst your 'rule of thirds' (which, incidentally, isn't exclusive to
| photography, but is a general principle used in many forms of visual art)
| may be mathematically correct at its junctures, it doesn't fit with how
| people think of time (ie, we think in days of 24 hours, not days of 12
| bi-hours).
|
|
| --
| Capt Scumbalino
|
|
|

Seamanship Question #32
 

"Joe" wrote
| If you do not give me a full point I will file a protest... and request
| the ASA points commitee to rule on this matter.

Give 'farmer' Joe ALL the points. He was right and posted first. Be fair.
Capt. Scumbalino's answer was more complete but it was the same. Actually,
give them each half the points.

Cheers,
Ellen

Seamanship Question #32
 

Ellen MacArthur wrote:
"Joe" wrote
| If you do not give me a full point I will file a protest... and request
| the ASA points commitee to rule on this matter.

Give 'farmer' Joe ALL the points. He was right and posted first. Be fair.
Capt. Scumbalino's answer was more complete but it was the same. Actually,
give them each half the points.

Cheers,
Ellen

....you have not been here long enough to have a say.

Sorry

Joe

Seamanship Question #32
 

"Joe" wrote
| ...you have not been here long enough to have a say.

Biting the hand that's feeding ya? Doh!
You've a lot to learn about women, Joe. We're entitled to a say any old time.
That's what we do best, ya know. (well, second best, wink wink!)

Cheers,
Ellen

Seamanship Question #32
 

Bull. He one of the worst examples. If he happens to occasionally say
something useful, it's mostly drowned out by his other common behavior. We
don't need any more sockpuppets, certainly not like him.

--
"j" ganz @@
www.sailnow.com

"Ellen MacArthur" wrote in message
reenews.net...
Everybody should read your post...

Very erudite of you, Capt. And you didn't lose your temper. And you
didn't call
me names. Your a good example for how newsgroup discussion should be done.

Cheers,
Ellen



"Capt. Scumbalino" wrote in message
...
| Ellen MacArthur wrote:
|
| Thanks for the explanation. So what's the difference between the
| rule of 12ths and the rule of thirds. In the rule of thirds the first
| two hours it goes down 1/4 which is the same as your 3/12th. The
| second two hours it goes down 1/2 which is the same as your 6/12th
| and the third two hours it goes down 1/4 which is the same as your
| 3/12th. See I got it right in spite of myself.
|
| It's based on the pretty-much universal fact that the time for the tide
to
| change from high to low water, and vice-versa, is pretty close to six
hours.
| Since we humans deal with time in chunks of one hour, the question we
ask
| is: "how much does the tide change in one hour?". Since the smallest
| fraction is one twelfth, just before and just after slack water, it's
| natural to refer to the tidal change during other hours in terms of the
same
| denominator. One twelfth in the first hour leads us to express the
change
| during the second as two twelfths, etc.
|
| Also, the larger the time slot, the greater the granularity. Imagine
you're
| waiting for the tide to rise enough to clear a sandbar. The rule of
thirds
| would have you waiting in chunks of two hours before you sail. The rule
of
| 12ths would keep you at anchor for chunks of one hour. Of course, plot
the
| heights on a graph over time, and you can pinpoint your departure time
| (rather, the time at which you can safely cross the sandbar) much more
| finely.
|
| Whilst your 'rule of thirds' (which, incidentally, isn't exclusive to
| photography, but is a general principle used in many forms of visual
art)
| may be mathematically correct at its junctures, it doesn't fit with how
| people think of time (ie, we think in days of 24 hours, not days of 12
| bi-hours).
|
|
| --
| Capt Scumbalino
|
|
|

Seamanship Question #32
 

I say give him his point. He needs them wherever he can get them. :-)

--
"j" ganz @@
www.sailnow.com

"Joe" wrote in message
oups.com...

Bart Senior wrote:
I'll give you 1/2 a point, because you did not explain how
it worked.


I was busy givin the lubber more rope to hang herself.

If you do not give me a full point I will file a protest... and request
the ASA points commitee to rule on this matter.

Joe


"Joe" wrote in message
oups.com...

Bart Senior wrote:
The point I wanted to make you covered. 1 point to Capt
Scumbalino.

NO FAIR! I said rules of 12 first, gimme my point you Scurvey dog!

Joe

Seamanship Question #32
 

ASA point? :-)

--
"j" ganz @@
www.sailnow.com

"Bart Senior" .@. wrote in message ...
Good point Jeff.

"Jeff" wrote

While the Rule of 12ths is a very handy tool for estimating the tide
height at any point in the cycle, I would be very careful of using to
extrapolate total range from one hour's observation. For instance, if
your observation were off by one inch, then you might mis-estimate the
full range by a foot.

On a related topic, sometimes people will claim that the Rule of 12ths
also applies to current estimation. This is generally not true. The
strength of the current through the cycle is highly dependent on the
local geography. In particular, the strong currents that are generated
by tidal differences on connected bodies of water (Hell Gate, Cape Cod
Canal, etc.) ramp up very quickly and their chart is more of a square
wave, than a sine.