On Dec 3, 9:12*pm, "Steve Lusardi" wrote:
Max,
Those compasses are not compasses. They are compass repeaters. The compass is elsewhere on the ship.Please reread my earlier
answer below. Another solution to the hand held swinging dilemma, might be to swing the compass positions where you would take
your sightings and simply create an offset table for each one. This too is common practice.
Steve


On a ship, the magnetic compass is usually directly atop monkey's
island. You can put a direction finder on its face and take magnetic
bearings. The only time I've ever needed to do this was when showing
an apprentice how it was done. In the wheelhouse and on the bridge
wings, they're all gimballed gyrocompass repeaters, of the stepping
kind.

I hadn't thought of creating a deviation table for likely positions of
use of the handheld compass. That's a great idea, and pretty much
solves my problem. I could just get a run-of-the-mill compass with a
hemispherical glass, and use a handheld (or compass-binoculars as
suggested elsewhere) for my magnetic bearings.

-m

On Thu, 3 Dec 2009 21:08:57 -0800 (PST), max camirand
wrote:

I could just get a run-of-the-mill compass with a
hemispherical glass, and use a handheld (or compass-binoculars as
suggested elsewhere) for my magnetic bearings.

When I started cruising back in the early 1970s that is how everyone
on small boats was doing navigation. Hi tech was having a radio
direction finder which had to be coordinated with compass headings,
and a rotating arm depth sounder. Really hi tech was having a Loran-A
set with the oscilloscope and manual pulse delay adjustments but
almost no one had one except for high end yachts with plenty of
battery power.

"max camirand" wrote in message
...
Hi group,

I'm looking for a real gimballed marine compass, with a flat face
usable with a direction-finder. All of the compasses I've found online
have a hemispherical glass face, which makes them useless for taking a
bearing. I also strongly suspect that hand-held bearing compasses are
useless on a steel boat such as mine.

The only flat-faced gimballed compasses I've found are desk
decorations.

I'm looking for something similar to a real ship's compass, without
the giant compensating balls & bar (I will compensate it with
magnets). Anyone know where they can be bought?

Regards,
-Maxime Camirand

Seem to be a few on ebay
#200412065291
#270495395158
#220521183176
May need to come up with a gimbal, but it'll be a lot cheaper that the 7500
euro job.

For me nothing beats this for shooting a bearing: #140364873863

mmc wrote:
"max camirand" wrote in message
...
Hi group,

I'm looking for a real gimballed marine compass, with a flat face
usable with a direction-finder. All of the compasses I've found online
have a hemispherical glass face, which makes them useless for taking a
bearing. I also strongly suspect that hand-held bearing compasses are
useless on a steel boat such as mine.

The only flat-faced gimballed compasses I've found are desk
decorations.

I'm looking for something similar to a real ship's compass, without
the giant compensating balls & bar (I will compensate it with
magnets). Anyone know where they can be bought?

Regards,
-Maxime Camirand

Seem to be a few on ebay
#200412065291
#270495395158
#220521183176
May need to come up with a gimbal, but it'll be a lot cheaper that the 7500
euro job.

For me nothing beats this for shooting a bearing: #140364873863


Marching compasses work well for me too. That one is a replica - so the
accuracy is an unknown. Better to search eBay for "marching compass".
There again, you don't want one that's marked in 0-400 graduations. Good
ol' 0-360 is the way to go!

:-)

Brian W

"brian whatcott" wrote in message
...
mmc wrote:
"max camirand" wrote in message
...
Hi group,

I'm looking for a real gimballed marine compass, with a flat face
usable with a direction-finder. All of the compasses I've found online
have a hemispherical glass face, which makes them useless for taking a
bearing. I also strongly suspect that hand-held bearing compasses are
useless on a steel boat such as mine.

The only flat-faced gimballed compasses I've found are desk
decorations.

I'm looking for something similar to a real ship's compass, without
the giant compensating balls & bar (I will compensate it with
magnets). Anyone know where they can be bought?

Regards,
-Maxime Camirand

Seem to be a few on ebay
#200412065291
#270495395158
#220521183176
May need to come up with a gimbal, but it'll be a lot cheaper that the
7500 euro job.

For me nothing beats this for shooting a bearing: #140364873863
Marching compasses work well for me too. That one is a replica - so the
accuracy is an unknown. Better to search eBay for "marching compass".
There again, you don't want one that's marked in 0-400 graduations. Good
ol' 0-360 is the way to go!

:-)

Brian W
Yeah, I have an old one that my "Uncle Sam" gave me. It's never led me
astray!