Well spotted.

Cheers MC

Donal wrote:

"Jonathan Ganz" wrote in message
...

The fog around here can be so thick as to prevent one
from seeing the bow of a 40 foot boat.


That is meaningless, unless we know how far you are from this 40 foot boat?



Regards


Donal
--

Rain can be heavy enough too!

Cheers MC

wrote:

On Tue, 23 Sep 2003 00:47:49 +0100, "Donal" wrote:


"Jonathan Ganz" wrote in message
...

The fog around here can be so thick as to prevent one
from seeing the bow of a 40 foot boat.

That is meaningless, unless we know how far you are from this 40 foot boat?



An excellent point, but I'm quite sure from personal experience that fog can be
thick enough that you can't see the bow of a 19 foot boat from the cockpit of
the same boat.

1927 datum?

Good grief.

Cheers MC

Scott Vernon wrote:

Well, right under the sea serpent and above the mermaid it says '' 1927
DATUM , Soundings in Feet at MLW''

Low Low Water Low Tide?????

SV

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message
...

How old is that chart? All of my US charts from the recent past use MLLW

as the datum for

soundings. I even checked in my Chesapeake ChartKit to see if they were

different.

OK - Here's a quiz: What's the meaning of LLWLT?

BTW, I thought of commenting on the "8 feet above MLW" also - around here

we have 10 foot

tides and flooding is measured above MHW

"Scott Vernon" wrote in message
...

Found the 'old' chart. It reads '' controlling depths in feet at Mean

Low

Water (MLW)''. AND; depths reffered to soundings (MLW)''.

Scotty


"Scott Vernon" wrote in message
...

Are you sure?
Don't keep charts at the house, thus the ''I believe'' .

SV



"The_navigator©" wrote in message
...

No they are not. Read the chart legend

Cheers MC

Scott Vernon wrote:
I believe that

charted depths are given at MLW and it's up to the sailor to know

the

tide

table and apply it.

We don't often use "spring tides" here in the States - people like RB would be saying they
only sail in Summer.

We just use MHW - that leads to excitement since the bridges will likely be lower than
their reported clearances once a day!

That reminds me - Happy Spring!


"The_navigator©" wrote in message
...
Heights on land and clearances are above MWHS -right?

Cheers MC

No, just MHW.

Scotty

"The_navigator©" wrote in message
...
Heights on land and clearances are above MWHS -right?

Cheers MC

What, Charlie Brown? Did I not state it was my ''old'' chart?

Scotty


"The_navigator©" wrote in message
...
1927 datum?

Good grief.

Cheers MC

Scott Vernon wrote:

Well, right under the sea serpent and above the mermaid it says '' 1927
DATUM , Soundings in Feet at MLW''

Low Low Water Low Tide?????

SV

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message
...

How old is that chart? All of my US charts from the recent past use
MLLW

as the datum for

soundings. I even checked in my Chesapeake ChartKit to see if they were

different.

OK - Here's a quiz: What's the meaning of LLWLT?

BTW, I thought of commenting on the "8 feet above MLW" also - around
here

we have 10 foot

tides and flooding is measured above MHW

"Scott Vernon" wrote in message
...

Found the 'old' chart. It reads '' controlling depths in feet at Mean

Low

Water (MLW)''. AND; depths reffered to soundings (MLW)''.

Scotty


"Scott Vernon" wrote in message
...

Are you sure?
Don't keep charts at the house, thus the ''I believe'' .

SV



"The_navigator©" wrote in message
...

No they are not. Read the chart legend

Cheers MC

Scott Vernon wrote:
I believe that

charted depths are given at MLW and it's up to the sailor to know

the

tide

table and apply it.

Hmmm. That's a worry. Might mean you'll need tide tables to decide if
you can pass an overhead...

Cheers MC

Jeff Morris wrote:

We don't often use "spring tides" here in the States - people like RB would be saying they
only sail in Summer.

We just use MHW - that leads to excitement since the bridges will likely be lower than
their reported clearances once a day!

That reminds me - Happy Spring!


"The_navigator©" wrote in message
...

Heights on land and clearances are above MWHS -right?

Cheers MC

But you're not that old are ya?

Cheers MC

Scott Vernon wrote:

What, Charlie Brown? Did I not state it was my ''old'' chart?

Scotty


"The_navigator©" wrote in message
...

1927 datum?

Good grief.

Cheers MC

Scott Vernon wrote:


Well, right under the sea serpent and above the mermaid it says '' 1927
DATUM , Soundings in Feet at MLW''

Low Low Water Low Tide?????

SV

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message
...


How old is that chart? All of my US charts from the recent past use

MLLW

as the datum for


soundings. I even checked in my Chesapeake ChartKit to see if they were

different.


OK - Here's a quiz: What's the meaning of LLWLT?

BTW, I thought of commenting on the "8 feet above MLW" also - around

here

we have 10 foot


tides and flooding is measured above MHW

"Scott Vernon" wrote in message
...


Found the 'old' chart. It reads '' controlling depths in feet at Mean

Low


Water (MLW)''. AND; depths reffered to soundings (MLW)''.

Scotty


"Scott Vernon" wrote in message
...


Are you sure?
Don't keep charts at the house, thus the ''I believe'' .

SV



"The_navigator©" wrote in message
...


No they are not. Read the chart legend

Cheers MC

Scott Vernon wrote:
I believe that


charted depths are given at MLW and it's up to the sailor to know

the


tide


table and apply it.

Nik wrote in
:

On Mon, 22 Sep 2003 22:49:08 GMT, Douglas Berry
wrote:

On 22 Sep 2003 14:03:08 -0700, several witnesses claim to have seen
(Doug Freyburger) scrawl a message on the wall:

Bertie the Bunyip wrote:
Doug Freyburger wrote:

Bertie has spent year trolling many newsgroups attacking Asatru
and this is one of his milder trolls. Having such a vulgar
and delusional obessive enemy complements Asatru. Folks can
learn much about your by who your enemies are, after all.
Bertie needs medical help.

To tell you the truth, I'm not terribly concerned with the
rampblings of someone who thinks a comic book character is God.

The Aesir hold a lot of concern for you to spend so many years
honoring them with your vulgar opposition. You clearly think
they are worth opposing.

Seek medical help.

huh? Who really cares what you do with your time? You want to
worship the Old Gods, go right ahead.

But don't be hurt when this crap gets cross-linked to alt.atheism,
where we find all religious beliefs rather silly at best.

And for your information, I wear a Tyr rune that was a gift from an
asatru friend. She gave to me as I was about to start chemotherapy.
Said it would help me focus my warrior side for the fight. I've worn
it everyday since. Not because I believe in Tyr, but because I
appreciated the gesture and what it meant.

Cool. I like that. There were atheists in Scandinavia back 1000+ years
ago, a small minority, but they did exist and the educated ones would
have used and known runes.

I once was a 'Revisable Atheist' cast after Russell Bertrand but not
for more than 10 ten years now...


Bwawhahwhahwhahwhahwhahwhahwhhahwhahwahwhhahwhahwh ahwhahwhahhwhahwhahwhahwh
ha!


Bertie

Yes - In case anyone is following this, let me explain:

Here in the States we use Mean High Water (MHW) as the datum for bridge clearances. This
means that, on average, half the tides will be higher than MHW, so the bridge will be
lower than expected. To make matters worse, with the common semi-diurnal tide, one tide
(the "higher high") will often be significantly higher than the other, so the discrepancy
can be large.

From chart 13270 of Boston harbor there is a table:

Height referred to datum of soundings (MLLW)
Mean Higher High Water 9.7 feet
Mean High Water 9.3 feet
Mean Low Water 0.3 feet
Extreme Low Water -3.0 feet

Thus, the average "higher high" is 0.4 feet above the datum used for bridge clearance.
However, today the Higher High is at 10.22 feet. almost a foot higher than the datum.
Anyone thinking they have a foot of clearance could be in for a nasty surprise!

I should add that a strong onshore breeze can often add an extra foot to the predicted
tides.

-jeff



"The_navigator©" wrote in message
...
Hmmm. That's a worry. Might mean you'll need tide tables to decide if
you can pass an overhead...

Cheers MC

Jeff Morris wrote:

We don't often use "spring tides" here in the States - people like RB would be saying
they
only sail in Summer.

We just use MHW - that leads to excitement since the bridges will likely be lower than
their reported clearances once a day!

That reminds me - Happy Spring!


"The_navigator©" wrote in message
...

Heights on land and clearances are above MWHS -right?

Cheers MC