Empathy List Archives

BA

bob Austin

Tue, Dec 5, 2006 7:02 PM

One wonders where he draws the line. We have voyaged well over 100,000 miles
offshore using a magnet compass in an auto pilot with no problems. The first
one was made from a WWII Bomb site compass, using two parallel tungsten wires.
Sure it hunted slightly Then came the fluxgate compasses--and computer driven
programs, Finely GPS and rate driven gyro compasses.... A lot of the voyaging
was done with a magnetic compass with a shadded card--and a photo electric
cell (Benmar). Worked very well--within feet after 100 miles often.

If you are that tight quarters, then take the wheel! If there is reason to
not trust the magnetic/fluxgate compass--take the wheel or use other modality
of steering.

If you are crossing an ocean--you may have a little wandering--but so what?

For the rest of the time, live with what ever compass system/GPS seems
expedient.

I don't see any advantage of an expenisve system, which may well be subject to
errors in critical situations (such as entering San Diego Harbor--and other
military bases when many of us find that GPS signals degrade).

You really want a system which will be very reliable and can be repaired if
necessary!---or you can do without! Very good basic axioms for all cruising
systems!

Regards,

Bob Austin

One wonders where he draws the line. We have voyaged well over 100,000 miles offshore using a magnet compass in an auto pilot with no problems. The first one was made from a WWII Bomb site compass, using two parallel tungsten wires. Sure it hunted slightly Then came the fluxgate compasses--and computer driven programs, Finely GPS and rate driven gyro compasses.... A lot of the voyaging was done with a magnetic compass with a shadded card--and a photo electric cell (Benmar). Worked very well--within feet after 100 miles often. If you are that tight quarters, then take the wheel! If there is reason to not trust the magnetic/fluxgate compass--take the wheel or use other modality of steering. If you are crossing an ocean--you may have a little wandering--but so what? For the rest of the time, live with what ever compass system/GPS seems expedient. I don't see any advantage of an expenisve system, which may well be subject to errors in critical situations (such as entering San Diego Harbor--and other military bases when many of us find that GPS signals degrade). You really want a system which will be very reliable and can be repaired if necessary!---or you can do without! Very good basic axioms for all cruising systems! Regards, Bob Austin

MM

Mike Maurice

Tue, Dec 5, 2006 7:33 PM

One wonders where he draws the line. We have voyaged well over 100,000 miles
offshore using a magnet compass in an auto pilot with no problems. The first
one was made from a WWII Bomb site compass, using two parallel tungsten wires.
S

Bob,
I hate to be the bearer of new knowledge, but a flux gate compass as
used on most modern autopilot systems is a far cry from the old magnetic
card systems that you refer to and with which many of us old timers are
familiar.

The flux gate is not nearly as effective, but it is a lot cheaper and
that is why it is being used. This partially explains the search for a
better solution than the flux gate. Trouble is, the alternatives are
expensive and magnetic compass technology might just become unusable if
the magnetic field dies. And even if it does not die, it is fading and
that is causing increased problems especially as one gets nearer the poles.

I understand your frustration with expensive solutions, but the
underlying incentives to find a better one are not without foundation.

Regards,
Mike

Capt. Mike Maurice
Beaverton Oregon(Near Portland)

> One wonders where he draws the line. We have voyaged well over 100,000 miles > offshore using a magnet compass in an auto pilot with no problems. The first > one was made from a WWII Bomb site compass, using two parallel tungsten wires. > S Bob, I hate to be the bearer of new knowledge, but a flux gate compass as used on most modern autopilot systems is a far cry from the old magnetic card systems that you refer to and with which many of us old timers are familiar. The flux gate is not nearly as effective, but it is a lot cheaper and that is why it is being used. This partially explains the search for a better solution than the flux gate. Trouble is, the alternatives are expensive and magnetic compass technology might just become unusable if the magnetic field dies. And even if it does not die, it is fading and that is causing increased problems especially as one gets nearer the poles. I understand your frustration with expensive solutions, but the underlying incentives to find a better one are not without foundation. Regards, Mike _____________________________________ Capt. Mike Maurice Beaverton Oregon(Near Portland)

PP

Peter Pisciotta

Tue, Dec 5, 2006 9:06 PM

I have delivered several Nordhavns with Furuno
satellite compasses, and many without (fluxgates).
While I don't recall being further north than the
Columbia River with a satellite compass-equipped so
cannot speak to wandering in high latitudes, I don't
every recall noticing a difference in how the boat
tracked. It could be that these were generally new
boats and the electronics still needed some tweaking,
and it could be that I'm not very observant about
these things (I'm with Bob - what's a little wandering
amongst friends?), but I just didn't find there to be
a discernable difference.

As a suggestion, before taking final delivery, make
sure ALL aspects of the eletronics have been
thoroughly tested, interfaced, and calibrated. A lot
has changed in the couple years I've been away from
the 'business,' but many boats I delivered were rushed
away from the dock. Consequently, some of the
eletronics were not dialed-in. PC interfaces were
commonly non-op, wxfax not setup, remote VHF handsets
not installed (or had the wrong connector), GPS not
interfaced to all displays, non-installed peripherals
(once had a depth sounder that hadn't been installed),
and a whole host of other minor maladies. All too
often, the boat was late getting completed and final
repairs bumped up against schedules so the last few
issues were left unresolved. My advice is to resist
the temptation to do it later - there will never be a
better time to resolve an issue than when it is at the
dock with all vendors nearby --- waiting final
payment.

Peter
www.SeaSkills.com
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com

I have delivered several Nordhavns with Furuno satellite compasses, and many without (fluxgates). While I don't recall being further north than the Columbia River with a satellite compass-equipped so cannot speak to wandering in high latitudes, I don't every recall noticing a difference in how the boat tracked. It could be that these were generally new boats and the electronics still needed some tweaking, and it could be that I'm not very observant about these things (I'm with Bob - what's a little wandering amongst friends?), but I just didn't find there to be a discernable difference. As a suggestion, before taking final delivery, make sure ALL aspects of the eletronics have been thoroughly tested, interfaced, and calibrated. A lot has changed in the couple years I've been away from the 'business,' but many boats I delivered were rushed away from the dock. Consequently, some of the eletronics were not dialed-in. PC interfaces were commonly non-op, wxfax not setup, remote VHF handsets not installed (or had the wrong connector), GPS not interfaced to all displays, non-installed peripherals (once had a depth sounder that hadn't been installed), and a whole host of other minor maladies. All too often, the boat was late getting completed and final repairs bumped up against schedules so the last few issues were left unresolved. My advice is to resist the temptation to do it later - there will never be a better time to resolve an issue than when it is at the dock with all vendors nearby --- waiting final payment. Peter www.SeaSkills.com Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com

RR

Ron Rogers

Tue, Dec 5, 2006 10:40 PM

Peter is making the point - you are buying a system, not a component. You
are paying for systems integration. In the information technology business,
I tried to get my clients to engage a contractor in a turn-key contract. You
install a network, then you must at least require the vendor to leave you
with one operating workstation and network printer in each subnet, etc.

Anybody (if they want to or have the time) can install a VHF or GPS; but not
everybody can use the right connectors to interface them or have the GPS
serve multiple client devices. So everything working together is what you
are paying for and that takes a good company with experience. Experience
is required because not everything is in the installation manual.

The true benefit of technology is having it work.

Ron Rogers

----- Original Message -----
From: "Peter Pisciotta" peter@seaskills.com

Peter is making *the* point - you are buying a system, not a component. You are paying for systems integration. In the information technology business, I tried to get my clients to engage a contractor in a turn-key contract. You install a network, then you must at least require the vendor to leave you with one operating workstation and network printer in each subnet, etc. Anybody (if they want to or have the time) can install a VHF or GPS; but not everybody can use the right connectors to interface them or have the GPS serve multiple client devices. So everything working together is what you are paying for and that takes a good company with *experience.* Experience is required because not everything is in the installation manual. The true benefit of technology is having it work. Ron Rogers ----- Original Message ----- From: "Peter Pisciotta" <peter@seaskills.com> | My advice is to resist | the temptation to do it later - there will never be a | better time to resolve an issue than when it is at the | dock with all vendors nearby --- waiting final | payment.

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