'Swinging' compass?
 

It's about time I adjust my steering compass (getting into foggy weather).

I've never done it myself before but it doesn't appear to be all that
difficult.

Here is my problem and question(s);

I'm on the Hood Canal. Plenty of open water and little or no water traffic.
However, there are no bouy lines, nav aids or designated ranges (there are
some navy ranges, but these are restricted).

I seldom have a crew so I must steer and take bearings and adjust the
compass by myself.

I have worked out my autopilot problems and it steers a very straight course
in calm water. The boat has a full keel so there is not 'dog tracking' due
to prop torque.

Here is what I wonder. Will my GPS COG be more accurate than hand bearings
(and eyeball measurement) of my autopilots steered course. Say, let the AP
steer long enough so the COG is steady for several minutes.

I have a Flux Gate compass as well but it doesn't have a self compensating
feature. To compensate it I have to use either the steering compass or the
COG or take bearings.

About the only factor that I think could effect the COG is a current set. I
think I can find a period at slack water where this will be nil.

Also, any recommendations on what to use for a non magnetic small screw
driver for turning the compensator magnets??

Thoughts, experiences??


Steve
s/v Good Intentions

'Swinging' compass?
 

Steve wrote:
It's about time I adjust my steering compass (getting into foggy

...
Thoughts, experiences??

Look in Eldridge for the article called "Magic Spot." It describes an easy
and straight-forward method using a hand-bearing compass. I've done it
several times over the years and my magnetic compass has always appeared to
be within a degree.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.tripod.com

'Swinging' compass?
 

Steve wrote:


Here is my problem and question(s);

I'm on the Hood Canal. Plenty of open water and little or no water traffic.
However, there are no bouy lines, nav aids or designated ranges (there are
some navy ranges, but these are restricted).

Break out your charts, and look for other things ..... distinct points
of land, that line up; charted structures (stacks, buildings, spires,
etc.), that you can line up with points of land, etc., to give you a
range with a known bearing.... dock facilities, breakwaters ..... as I
say, anything that will give a range and bearing you can use (I'd
probably stay away from buoys, except as a last resort).

otn

'Swinging' compass?
 

My magnetic compass came with a brass screwdriver.

"Listen to the live broadcast of 'Nautical Talk Radio' with Captain Lou every
Sunday afternoon from 4 - 5 (Eastern Standard Time) on the web at
www.959watd.com or if you are in Boston or Cape Cod set your radio dial to
95.9FM.

'Swinging' compass?
 

Yah! I think mine did also, but Who Knows where it is now??

I have some small brass brazing rod, so I think I will make one..

Steve
s/v Good Intentions

'Swinging' compass?
 

My boat has only been commisioned for 13 months and I keep postponing the
steering compass adjustment, because I'm still loading gear/spares aboard
and installing electrical equipment that will, no doubt effect the compass..

Then I got to thinking, I'm a DIYer and always wanted to learn how to do
this.. The instructions that came from Richie make it sound so easy and I
recently found a computer generated deviation table program..

It may take me a little time to do it the first time but once I have done it
once, I won't have any hesitation about re-swinging the compass after I get
all my gear on board or head offshore.

During this summer I seldom took the cover off the compass because I had
already noticed some major error on certian points. I suspect my engine is
causing some of this since it is only about 20 inches below and slightly aft
of this bulkhead mounted compass. Not an idea situation but I had no choice
in the location since this is a toller steered boat. The only location that
I could see from the tiller was on the forward face of the cockpit foot
well.

I was expecting to do and 'self adjust/compensate' on my fluxgate, like you
do with a autopilot, but when I read the manual, I found that you have to
swing the compass and enter the correct bearing at about every 60 degrees.

Anyway, it all seems like some good winter projects.

Steve
s/v Good Intentions