Joe wrote:

I suspect that the speed you're looking for is the speed that would be
sailed through the water to acheive the desired course - speed made good is
the speed over the ground, isn't it (ie resultant of course/speed sailed and
drift/set)? I'll assume you're looking for course/speed through the water to
acheive the desired course and speed in the given conditions...


If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots

069 at 9.17 knots.


If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots

083 at 11.61 knots.


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

277 at 14.78 knots.


--
Wally
www.artbywally.com
www.wally.myby.co.uk

"Wally" wrote in message ...
Joe wrote:

I suspect that the speed you're looking for is the speed that would be
sailed through the water to acheive the desired course - speed made good is
the speed over the ground, isn't it

Yes, Im talking about doing a DR plot SMG & CMG are the actual course
and speed you do.



(ie resultant of course/speed sailed and
drift/set)? I'll assume you're looking for course/speed through the water to
acheive the desired course and speed in the given conditions...


If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots

069 at 9.17 knots.

Sorry Wally you are incorrect.

If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots

083 at 11.61 knots.

Very close to the course to steer, and your speed is off by almost a
knot


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

277 at 14.78 knots.

277 is way off, but your real close on the speed, but not right on.

Sorry you flunked

Next! Come on Jax... show us what a skilled offshore navigator you
are!
Our you just a big mouth blowhard!

It's just a simple DR plot... Mr offshore bigshot!

joe, you don't understand the definition of the term "DR".

From: (Joe)
Date: 7/16/2004 2:43 PM Eastern Daylight Time
Message-id:

"Wally" wrote in message
...
Joe wrote:

I suspect that the speed you're looking for is the speed that would be
sailed through the water to acheive the desired course - speed made good is
the speed over the ground, isn't it

Yes, Im talking about doing a DR plot SMG & CMG are the actual course
and speed you do.



(ie resultant of course/speed sailed and
drift/set)? I'll assume you're looking for course/speed through the water
to
acheive the desired course and speed in the given conditions...


If you want to sail a course of 080, at a speed of 10 knots and you
sail thru a current having an estimated set of 140 and a drift of two
knots

069 at 9.17 knots.

Sorry Wally you are incorrect.

If you want to sail a course of 095 through a current having a set of
170 and a drift of 2.5 knots, using a speed of 12 knots

083 at 11.61 knots.

Very close to the course to steer, and your speed is off by almost a
knot


You want to sail a course of 265 and a speed of 15 knots through a
current having a set of 185 and a drift of 3 knots

277 at 14.78 knots.

277 is way off, but your real close on the speed, but not right on.

Sorry you flunked

Next! Come on Jax... show us what a skilled offshore navigator you
are!
Our you just a big mouth blowhard!

It's just a simple DR plot... Mr offshore bigshot!

JAXAshby wrote:
joe, you don't understand the definition of the term "DR".

jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn

over the knee, if you expand the definition to include gps charterplotters,
anything is possible.

same same if you expand the definition of breakfast eggs to include three
bricks of 24-k gold, you would be rich.

DR is speed vs time vs direction pointed, and your best guess as to where that
puts you. that's it, nothing more.

Some people believe that guessing as to current direction and strength and
guessing as to boat drift due to wind speed and direction improves their best
guess as to where they are, but it doesn't.

joe, you don't understand the definition of the term "DR".

jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn

JAXAshby wrote:
over the knee, if you expand the definition to include gps charterplotters,
anything is possible.

If I use a gps chart plotter (assuming gps working and connected) then I
have a fix not a "DR" position

same same if you expand the definition of breakfast eggs to include three
bricks of 24-k gold, you would be rich.

DR is speed vs time vs direction pointed, and your best guess as to where that
puts you. that's it, nothing more.

As stated before, you know "A" definition of DR, nothing more.
All this and your last post tell me is that you have extremely limited
experience and knowledge of the subject.

Some people believe that guessing as to current direction and strength and
guessing as to boat drift due to wind speed and direction improves their best
guess as to where they are, but it doesn't.

Statement shows limited experience.

DR has been used for centuries and is still used today. As such, it's
used to travel new routes as well as those that have been frequently
done in the past.
For this reason, many sailors have expanded on the term "DR" to include
past experience; their knowledge of how their vessel reacts to winds,
known currents; soundings, etc. .... i.e. they use these factors to
improve/fine tune their "DR" plots.
As Bowditch states, your definition is correct, but it's not universal.
For you, "DR" is speed/time/direction and that's OK since it's probably
all your experience can handle, but for many others, it includes a
number of other factors beyond your capabilities which don't give a
position and can be in error, but from experience, helps improve what
*THEY* call "DR".

otn



joe, you don't understand the definition of the term "DR".

jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn

no, over the knee, you DO have DR **if** you expand the definition of DR as you
did prior. I didn't expand it, you did.

over the knee, if you expand the definition to include gps charterplotters,
anything is possible.

If I use a gps chart plotter (assuming gps working and connected) then I
have a fix not a "DR" position

over the knee, give it up for the kriste sakes. once ah-fricken-ghen you are
arguing a physical impossibilty. most every scientist -- and certainly every
last physicist -- on the planet is laughing at you.

You, over the knee, have a better chance of arguing astrology is valid.


DR has been used for centuries and is still used today. As such, it's
used to travel new routes as well as those that have been frequently
done in the past.
For this reason, many sailors have expanded on the term "DR" to include
past experience; their knowledge of how their vessel reacts to winds,
known currents; soundings, etc. .... i.e. they use these factors to
improve/fine tune their "DR" plots.
As Bowditch states, your definition is correct, but it's not universal.
For you, "DR" is speed/time/direction and that's OK since it's probably
all your experience can handle, but for many others, it includes a
number of other factors beyond your capabilities which don't give a
position and can be in error, but from experience, helps improve what
*THEY* call "DR".

otn



joe, you don't understand the definition of the term "DR".

jax, you don't know the definition of "DR", you only know A definition
of "DR", and the fact that *you* don't understand this is not surprising.

otn

Statement shows limited experience.

over the knee, that is the very same arguement put forth by true believers as
to why they believe astrology is valid.

over the knee, you know more about astrology than physics. do you believe in
astrology??

JAXAshby wrote:

over the knee, if you expand the definition to include gps charterplotters,
anything is possible.

same same if you expand the definition of breakfast eggs to include three
bricks of 24-k gold, you would be rich.

DR is speed vs time vs direction pointed, and your best guess as to where that
puts you. that's it, nothing more.

Some people believe that guessing as to current direction and strength and
guessing as to boat drift due to wind speed and direction improves their best
guess as to where they are, but it doesn't.


Oh boy here we go again.

Cheers