On Sun, 16 Jan 2005 23:34:23 -0500, Rodney Myrvaagnes
wrote:

On Sun, 16 Jan 2005 23:17:11 GMT, "Roger Long"
wrote:

That rings a bell and I think you might be right. The shoal being
shallower than charted may have been a secondary factor.

I don't think it would have been GPS in those days. Probably Loran.


Can't tell what you are talking about. Both the QE2 and Nantucket
shoals incident are quite recent. The QE2 was a chart problem, since
corrected, and had nothing to do with autopilot or any other automated
gear.


I heard they had more of a squat problem. As in they forgot to figure
in the ship's squat at their speed over the shoal.
Mark E. Williams

snip

Jim Donohue wrote:


Actually I am by training and a long career an engineer. It is what
seperates us OTN...you react I go for understanding.

No. I reason, while you go for understanding based solely on science and
engineering. Your problem is you don't understand how to use or make use
of the science and engineering you know, within the real world that
exist around us.


Sure your socks are soaked in salt...so perhaps is your brain. I think with
your long time frame at mis-understanding this stuff you are very well
qualifled for say Chief Officer on the Royal Majesty. He did a truly fine
job of successfully identifying the unidentifyable...as I am sure you would.
But he was really salty.

LOL I don't mis-understand this "stuff". If I had been Master or Chief
Officer on that ship, I would have realized early that "WE" had a
problem. "Salty" is not saying you have such and such a license or you
have made such and such trips. Salty is saying you've always made them
safely, taking into consideration the various conditions and noting the
possible errors in your systems and actions.


Wish you could have been on our little trip with the "freeway" Captain...you
could have helped him set the anchor.

LOL would have probably sat back and had a good laugh, as long as his
actions didn't endanger anyones safety.

I prefer to navigate around floating objects as well as fixed ones. If you
ignore the floaters I assure you something you would rather avoid is likely
to occur.

Jim


I try to ignore nothing ( not always successful), but I also try to
learn something new, every time I'm on the water, no matter how
insignificant, and unlike you, I'm still learning, not hung up on the
god, GPS.
The recent rains in S. Ca. have shown all of us, not only ways to see
currents, but the need to see the possibilities of way we can avoid many
of those dangerous floating hazards.

otn

Enjoying your little tiffs you guys. Obviously you both have a certain
amount of sense as you are both still around or else the gods have been
particularly kind....

Just come back from Fiji where we stayed for several months. Many of the
charts predate GPS's and the result is that they may be out by as much as
..33nm from the GPS position. Also the beacons shown may or may not exist due
to cyclonic weather. What does exist still is the reef system and is quite a
good idea to avoid. We watched 2 rather expensive yachts have arguments with
a reef and heard of a number more. Reefs are not much of a problem on nice
sunny days but when overcast it may become impossible to "eyeball". What to
do depends upon the circumstances.

However using GPS alone would shorten the cruise and you wouldn't have the
bother of sailing home.

jofra

"Jofra" wrote in message
...
Enjoying your little tiffs you guys. Obviously you both have a certain
amount of sense as you are both still around or else the gods have been
particularly kind....

Just come back from Fiji where we stayed for several months. Many of the
charts predate GPS's and the result is that they may be out by as much as
.33nm from the GPS position. Also the beacons shown may or may not exist
due to cyclonic weather. What does exist still is the reef system and is
quite a good idea to avoid. We watched 2 rather expensive yachts have
arguments with a reef and heard of a number more. Reefs are not much of a
problem on nice sunny days but when overcast it may become impossible to
"eyeball". What to do depends upon the circumstances.

However using GPS alone would shorten the cruise and you wouldn't have the
bother of sailing home.

jofra

Year before last we had a 38 foot sailboat enter Minerva reef by GPS. After
a couple of days decided to go out the other side via visual...Guess
what...Well they salvaged much of the equipment I understand. Seems to me
visual shortened their cruise and cost a lot of money.

Jim Donohue

Jim

Several students of DeVry Institute of Technology in Calgary, Alberta, Canada did just that with
four GPS receivers, a computer, and some specialized software. Four inch accuracy. **No kidding.**
I don't know if they had DGPS units for the experiment. The experiment snowballed from an earlier
experiement that won them some sort of international championship in 2001 when they got an
automated, computer guided model helicopter to lift off, fly 3 meters and hover over a four inch
target, hook onto it and then fly back and land. No manual control what-so-ever. Pretty neat if
you ask me! (But I heard they had to drive at only a walking pace).

"Jack Dale" wrote:
How many out there are prepared to drive their car using GPS only?

On Mon, 17 Jan 2005 19:45:54 -0600, Maynard G. Krebbs
wrote:

On Sun, 16 Jan 2005 23:34:23 -0500, Rodney Myrvaagnes
wrote:

On Sun, 16 Jan 2005 23:17:11 GMT, "Roger Long"
wrote:

That rings a bell and I think you might be right. The shoal being
shallower than charted may have been a secondary factor.

I don't think it would have been GPS in those days. Probably Loran.


Can't tell what you are talking about. Both the QE2 and Nantucket
shoals incident are quite recent. The QE2 was a chart problem, since
corrected, and had nothing to do with autopilot or any other automated
gear.


I heard they had more of a squat problem. As in they forgot to figure
in the ship's squat at their speed over the shoal.
Mark E. Williams

Right! The pilot and the long-time skipper colluded to make an
elementary mistake. Look at the chart, before and after.

It is possible that squat may have lengthened the tear in the hull,
but if the chart had been correct they wouldn't have touched at all.

Rodney Myrvaagnes NYC J36 Gjo/a


"Be careful. The toe you stepped on yesterday may be connected to the ass you have to kiss today." --Former mayor Ciancia

On Tue, 18 Jan 2005 05:13:19 GMT, "Richard P." wrote:

Several students of DeVry Institute of Technology in Calgary, Alberta, Canada did just that with
four GPS receivers, a computer, and some specialized software. Four inch accuracy. **No kidding.**
I don't know if they had DGPS units for the experiment. The experiment snowballed from an earlier
experiement that won them some sort of international championship in 2001 when they got an
automated, computer guided model helicopter to lift off, fly 3 meters and hover over a four inch
target, hook onto it and then fly back and land. No manual control what-so-ever. Pretty neat if
you ask me! (But I heard they had to drive at only a walking pace).

"Jack Dale" wrote:
How many out there are prepared to drive their car using GPS only?

I live in Calgary. I hope they send out a notice to drivers when they
do it.

My lack of faith in GPS was reinforced when the chartplotter showed
my boat on land while safely anchored stern-to in Princess Bay on
Wallace Island.

On the other hand, I did navigate through the rocks in Race Passage in
last year's Swiftsure using GPS. I had a paper chart in front of me
while I did it.

Jack

Jack Dale wrote:


My lack of faith in GPS was reinforced when the chartplotter showed
my boat on land while safely anchored stern-to in Princess Bay on
Wallace Island.

On the other hand, I did navigate through the rocks in Race Passage in
last year's Swiftsure using GPS. I had a paper chart in front of me
while I did it.

Jack



This is the problem/situation that many are noting, especially those
using chart plotters.
During most piloting exercises where we're underway, many minor
discrepancies between the chart plotter position and actual will not be
readily apparent as they are relatively small and due to the fact you
are normally giving a "safe berth" to most points you are passing, of
little consequence.
However, once you are anchored or moored or even working around a tight
docking situation, these discrepancies DO become readily apparent.
In most cases, I'm dealing with chart plotters on different vessels (all
gyro stabilized) that are using same/different/similar electronic
packages and unknown chart data (some charts I know to be older versions).
Depending on the vessel, I've noted errors of from @10' - 100' of a
variable nature (sometimes between trips, sometimes between vessels).
in this particular port. The most obvious being when alongside the dock.
Personally, when piloting, naturally my first choice is eyeball, but if
I have a GPS readout handy to where I'm standing I use it to confirm
speed and get a backup to my sense of set and drift, and where I have a
chart plotter to look at, I glance at it for a "birdseye" view, though I
put more weight on the "birdseye" view from the radar where accuracy is
concerned, as long as the particular radar picture is clear.
Naturally, what I'm discussing is for a particular port. Each port and
set-up will vary/differ .... my main point is that you should use
everything at hand, be aware of possible drawbacks to each and make
maximum use of the positives.

otn

Year before last we had a 38 foot sailboat enter Minerva reef by GPS.
After a couple of days decided to go out the other side via visual...Guess
what...Well they salvaged much of the equipment I understand. Seems to
me visual shortened their cruise and cost a lot of money.

Jim Donohue

Jim

Thanks for comments Jim but not sure what point you are making. Are you
suggesting that if they had gone out of the Minerva Reef using GPS they
would still have their yacht? Possibly they would. I would like to know more
about the case. What were the conditions like, time of day, position of the
sun, cloud cover, sea conditions? Also when they went inside the reef using
GPS did they know the accuracy of the chart in relation to the GPS?

cheers

jofra

On Tue, 18 Jan 2005 17:59:40 GMT, otnmbrd
wrote:
I've noted errors of from @10' - 100' of a
variable nature (sometimes between trips, sometimes between vessels).
in this particular port. The most obvious being when alongside the dock.

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

There are fixed errors also. I live on the south side of a 120 foot
canal. Four different WAAS GPS units consistently show the boat
docked on the north side. Most likely chart error but who knows?