Someone asked for an easy way to figure out how fast Skip was traveling.
Well I found a nice little on-line Haversine (the function to compute
the Great Circle distance between two points) calculator.

http://www.movable-type.co.uk/scripts/latlong.html

Just input the coordinates from two of Skips messages that are one hour
apart and out pops the distance in km. You can do a bit of conversion
from there.

From Skips' 1257 abd 1357 points he only traveled 10Kms, about 6nm.

Cheers
Marty

On Sun, 05 Oct 2008 14:23:08 -0400, Marty wrote:

Someone asked for an easy way to figure out how fast Skip was traveling.
Well I found a nice little on-line Haversine (the function to compute
the Great Circle distance between two points) calculator.

http://www.movable-type.co.uk/scripts/latlong.html

Just input the coordinates from two of Skips messages that are one hour
apart and out pops the distance in km. You can do a bit of conversion
from there.

From Skips' 1257 abd 1357 points he only traveled 10Kms, about 6nm.


Cool, good find.

Here's another site that uses a more convenient (for SPOT data) input
format, and returns nautical miles:

http://jan.ucc.nau.edu/~cvm/latlongdist.html

Here's an example from 3:47PM to 5:47PM where they covered 8 nautical
miles in two hours for a VMG of 4 kts. That's not all that bad
considering that they are probably under sail with a knot or two of
Gulf Sream current against them. Looks like they're heading for the
cut through channel in the middle of Frying Pan (Cape Fear) Shoals.

Distance Calculation Results

Distance between 33.9459N 77.1566W and 33.9139N 77.3133W is
8.0482 nautical miles

Source
Latitude : 33.9459N Longitude: 77.1566W

Destination
Latitude : 33.9139N Longitude: 77.3133W

Units for results nautical miles

"Wayne.B" wrote in message
news
On Sun, 05 Oct 2008 14:23:08 -0400, Marty wrote:

Someone asked for an easy way to figure out how fast Skip was traveling.
Well I found a nice little on-line Haversine (the function to compute
the Great Circle distance between two points) calculator.

http://www.movable-type.co.uk/scripts/latlong.html

Just input the coordinates from two of Skips messages that are one hour
apart and out pops the distance in km. You can do a bit of conversion
from there.

From Skips' 1257 abd 1357 points he only traveled 10Kms, about 6nm.


Cool, good find.

Here's another site that uses a more convenient (for SPOT data) input
format, and returns nautical miles:

http://jan.ucc.nau.edu/~cvm/latlongdist.html

Here's an example from 3:47PM to 5:47PM where they covered 8 nautical
miles in two hours for a VMG of 4 kts. That's not all that bad
considering that they are probably under sail with a knot or two of
Gulf Sream current against them. Looks like they're heading for the
cut through channel in the middle of Frying Pan (Cape Fear) Shoals.
snip

Skippy would be better off going around Cape Fear with plenty of offing
rather than trying that yacht channel at night. It appears the winds are
nothing to be concerned about so the seas can't bee too bad. The only
advantage of transiting the shoal water through the channel might be a
little less current but depending upon the state of the tide there could
even be more current in the cut than going around the Frying Pan shoals.

I'd go outside at night and inside during the day.

Wilbur Hubbard

Wayne.B wrote:
On Sun, 05 Oct 2008 14:23:08 -0400, Marty wrote:

Someone asked for an easy way to figure out how fast Skip was traveling.
Well I found a nice little on-line Haversine (the function to compute
the Great Circle distance between two points) calculator.

http://www.movable-type.co.uk/scripts/latlong.html

Just input the coordinates from two of Skips messages that are one hour
apart and out pops the distance in km. You can do a bit of conversion
from there.
From Skips' 1257 abd 1357 points he only traveled 10Kms, about 6nm.


Cool, good find.

Here's another site that uses a more convenient (for SPOT data) input
format, and returns nautical miles:

http://jan.ucc.nau.edu/~cvm/latlongdist.html

Here's an example from 3:47PM to 5:47PM where they covered 8 nautical
miles in two hours for a VMG of 4 kts. That's not all that bad
considering that they are probably under sail with a knot or two of
Gulf Sream current against them. Looks like they're heading for the
cut through channel in the middle of Frying Pan (Cape Fear) Shoals.

Distance Calculation Results

Distance between 33.9459N 77.1566W and 33.9139N 77.3133W is
8.0482 nautical miles

Source
Latitude : 33.9459N Longitude: 77.1566W

Destination
Latitude : 33.9139N Longitude: 77.3133W

Units for results nautical miles



Thanks Wayne, the one I posted lets you use decimal degrees, the only
thing is the return in KMs, just divide by 1.85 and you get nautical
miles. I put Skip's numbers in for a 12 hour period and got 60nm, not
to bad at all, 120 mile days are nothing to be sneered at.

Cheers
Marty

Wilbur Hubbard wrote:

snip

Skippy would be better off going around Cape Fear with plenty of offing
rather than trying that yacht channel at night. It appears the winds are
nothing to be concerned about so the seas can't bee too bad. The only
advantage of transiting the shoal water through the channel might be a
little less current but depending upon the state of the tide there could
even be more current in the cut than going around the Frying Pan shoals.

I'd go outside at night and inside during the day.

I will defer to your local, (perhaps loco?) knowledge. Given modern nav
systems though, I really don't see to much issue with doing it at night,
tidal currents and those due the Gulf Stream would take precedence for me.

Cheers
Marty

Wilbur Hubbard

"Marty" wrote in message
...
Wilbur Hubbard wrote:

snip

Skippy would be better off going around Cape Fear with plenty of offing
rather than trying that yacht channel at night. It appears the winds are
nothing to be concerned about so the seas can't bee too bad. The only
advantage of transiting the shoal water through the channel might be a
little less current but depending upon the state of the tide there could
even be more current in the cut than going around the Frying Pan shoals.

I'd go outside at night and inside during the day.

I will defer to your local, (perhaps loco?) knowledge. Given modern nav
systems though, I really don't see to much issue with doing it at night,
tidal currents and those due the Gulf Stream would take precedence for me.

I refuse to take a chance, ever, on going aground when there's a safe,
viable alternative to taking the chance. One would never wish to go aground
on the Cape Fear shoals. It could cost you your boat. Not that they are hard
or rocky or anything like that but there's currents and tides thunder storms
and not much civilization or assistance around.

Wilbur Hubbard

On Sun, 5 Oct 2008 19:05:53 -0400, "Wilbur Hubbard"
wrote:

One would never wish to go aground
on the Cape Fear shoals. It could cost you your boat. Not that they are hard
or rocky or anything like that but there's currents and tides thunder storms
and not much civilization or assistance around.

That's all true but the channel is well marked with a couple of large
buoys that are exactly where the chart shows them to be. We've been
through there twice at night and had no problem. Adverse current
inside is about half that of going around the end, it's about 20 miles
shorter, and they've got nearly perfect weather tonight. Winds are
aft from the NE at 10 to 12 and seas are less than 3 ft, about as good
as it gets.

I'd definitely go outside in high winds or adverse visibility however.

On Sun, 05 Oct 2008 18:54:41 -0400, Marty wrote:

I put Skip's numbers in for a 12 hour period and got 60nm, not
to bad at all, 120 mile days are nothing to be sneered at.

I agree. It's a big heavy cruising boat that is not exactly over
rigged, and they have been in light to moderate winds for the most
part.

Wilbur Hubbard wrote:


I refuse to take a chance, ever, on going aground when there's a safe,
viable alternative to taking the chance. One would never wish to go
aground on the Cape Fear shoals. It could cost you your boat. Not that
they are hard or rocky or anything like that but there's currents and
tides thunder storms and not much civilization or assistance around.

It may be premature to decide where he's going, it'd still be just a
small change to port to go SE of the yacht channel, the chart I'm
looking at, 11520 seems to indicate he could expect six to eight fathoms
there.

Cheers
Martin

Wilbur Hubbard

Wayne.B wrote:
On Sun, 5 Oct 2008 19:05:53 -0400, "Wilbur Hubbard"
wrote:

One would never wish to go aground
on the Cape Fear shoals. It could cost you your boat. Not that they are hard
or rocky or anything like that but there's currents and tides thunder storms
and not much civilization or assistance around.

That's all true but the channel is well marked with a couple of large
buoys that are exactly where the chart shows them to be. We've been
through there twice at night and had no problem. Adverse current
inside is about half that of going around the end, it's about 20 miles
shorter, and they've got nearly perfect weather tonight. Winds are
aft from the NE at 10 to 12 and seas are less than 3 ft, about as good
as it gets.

I'd definitely go outside in high winds or adverse visibility however.


Looking his last data, I'm thinking he may be planning to go just inside
R12, 18 miles SE of the channel.

Cheers
Marty