Not necessarilly. Great Lake charts are in statute miles and use Poly
Conic projection, rather than the Mercator that the off shore charts
use.
Reply
********************
An exception somewhat proving the rule.
I'm not familiar with charts for the Great Lakes, of course, but it's
surprising they wouldn't follow the convention of the majority of the
world.
Do Great Lakes sailors discuss vessel speed or wind speeds in knots or
MPH?
==================================

I'm told that the Lakes use statute miles because of the land mass
involved in the charts. However, had the St. Lawrence Seaway came into
being sooner, bringing "salties" to the Lakes, the chartmakers might
have decided to use the "off-shore" type of chart and nautical miles to
avoid confusion. As far as speed terminology, you hear both.

On Fri, 15 Apr 2005 10:33:48 -0400, Black Dog
wrote:

and occasionally some drunken lubber will throw in KPH too

==========================

Personally I've always had a preference for furlongs per fortnignt.

On Fri, 15 Apr 2005 15:05:11 -0400, Wayne.B
wrote:

On Fri, 15 Apr 2005 10:33:48 -0400, Black Dog
wrote:

and occasionally some drunken lubber will throw in KPH too

==========================

Personally I've always had a preference for furlongs per fortnignt.

I always thought cubits per parsec was a good method.

Later,

Tom

On Fri, 15 Apr 2005 21:21:22 GMT, Gene Kearns
wrote:

On Fri, 15 Apr 2005 20:15:02 GMT, Short Wave Sportfishing
wrote:

On Fri, 15 Apr 2005 15:05:11 -0400, Wayne.B
wrote:

On Fri, 15 Apr 2005 10:33:48 -0400, Black Dog
wrote:

and occasionally some drunken lubber will throw in KPH too

==========================

Personally I've always had a preference for furlongs per fortnignt.

I always thought cubits per parsec was a good method.


Let it go, guys.... this is getting too close to how long you taught
your wife a foot was...

Um...

¿Que?

On Fri, 15 Apr 2005 19:12:36 GMT, Red Cloud©
wrote:

The windspeed during the storm was increasing by roughly 3 KPH!

============================================

In Europe it is very common to measure wind speed in meters per
second. There is a handy conversion however taught to me by a Swede
who used to crew on my former racing boat. If you double meters per
second, it is almost exactly equal to knots. Try it, it works.

On Wed, 13 Apr 2005 13:51:46 -0400, "The real ME"
wrote:

In another posts someone asked questions concerning nautical terms.

A knot is what you put in a line (not a rope), a MPH is a speed
measurment.

On Sat, 16 Apr 2005 11:23:42 GMT, Red Cloud®
wrote:

On Fri, 15 Apr 2005 23:20:15 -0400, Wayne.B
wrote:

On Fri, 15 Apr 2005 19:12:36 GMT, Red Cloud©
wrote:

The windspeed during the storm was increasing by roughly 3 KPH!

============================================

In Europe it is very common to measure wind speed in meters per
second. There is a handy conversion however taught to me by a Swede
who used to crew on my former racing boat. If you double meters per
second, it is almost exactly equal to knots. Try it, it works.

My only point was that there IS a correct way to use the term "KPH", although it
is frequently used incorrectly. "Knots" includes an implied "per hour", so the
only time you would add "Per Hour" after knots, (KPH) would be to describe by
how much speed something (wind, boat, dolphins) was increasing or decreasing on
average referenced to an elapsed hour.
===================================

Silly me. I assumed you were talking about Kilometers Per Hour
knowing full well that Knots Per Hour would be redundant and
repetitious and incorrect and redundant and repetitious and ...

My only point was that there IS a correct way to use the term "KPH",
although it
is frequently used incorrectly. "Knots" includes an implied "per hour",
so the
only time you would add "Per Hour" after knots, (KPH) would be to
describe by
how much speed something (wind, boat, dolphins) was increasing or
decreasing on
average referenced to an elapsed hour.

rusty redcloud


***********

"Knots per hour" is an incorrect usage.

Since a 1 knot speed is equal to a nautical mile per hour, some people
might wonder why they are spelled differently. "Knot" isn't a
misspelling of "naut".

Using knots to measure speed dates back to the days of sail. A
midshipman or the quartermaster would be required to measure the speed
of a vessel at regular intervals, make a note of it in a log, and make
report to the master and/or navigator.

To measure speed, a wooden, wedge-shaped board (speed log) was tossed
overboard. A spooled line would be attached to the board, and the line
would be allowed to pay out as the board was left in the vessel's wake.
The line payed out for a short but precisely measurable period of time.
(A short interval sand glass would have been used)
A series of knots were tied in the line at known intervals, and the
seaman measuring the speed would count the number of knots that slipped
through his fingers during the measuring period. Speed would be
reported as "eight knots" if eight knots slipped though the fingers of
the party doing the measuring.

The math is simple, but ingenious. The time interval will be a specific
portion of an hour.
Say for example the measuring exercise took place for 30 seconds after
the "log" splashed down- that would be 1/120th of an hour. If the knots
were tied in the line 1/120th of a nautical mile (about 47 and 1/4
feet) apart then at 1 nautical mile per exactly 1 "knot" would pay out
during the measuring. If 6 X approx 47 1/4 feet payed out in 30
seconds, then the vessel would cover six nautical miles in an hour, or
be making a speed of six knots.

A boat was traveling at 5 knots. It speeds up gradually at a rate of 2
Knots per
Hour.


********************

A vessel's speed may be recorded at specific periods of time, but
nobody familiar with the movement of a boat that is effected by winds,
currents, etc would presume that the change had been, or even likely
would be, evenly graduated over
a period of time.

If you boat is making 5 knots at 0500 and 11 knots at 0800, that
doesn't mean that it sped up at a rate of 2 knots per hour. It is
entirely possible that the boat didn't speed up until 0759, when the
wind shifted.

Here's a new term to keep you confused: AVERAGE

sheesh!


rusty redcloud


*********

Thank you.

Here's one for you, as well. NAVIGATION

There is no navigational use for determining the average hourly change
in knots during a previous period of time. It cannot be used to
forecast future changes, will almost certainly be non-linear, and could
lead to some wildly erroneous conclusions about position.

It is common to project present speed, particularly for short
intervals, to predict future position. How fast you were running
yesterday, or even several hours ago becomes meaningless. The average
rate of hourly change in knots made would be useful for evaluating tits
on a boar.