There's more to it than you think:

http://www.whautopilots.com/Application%20Notes/


Steel yachts may be floating magnets (hard iron problems) or just have a lot
steel paths to deviate external magnetic fields(soft iron problems).

The hard iron effects can come about when the vessel is moored in a
North/South direction for long periods of time (and by other, less
understood reactions, from welding and cutting). Hard iron magnetism can be
removed by applying a large AC magnetic field to the entire vessel. This
"degaussing " technique was used on large commercial and military vessels
about 60 years ago. The local degaussing station was located under the water
at Jefferson Head (just north of Bainbridge Island, WA). The shore control
building would apply huge AC currents to a giant underwater coil just as a
vessel positioned its self directly over the coils. The entire steel vessel
would hum at 60 Hz! I know of no existing degaussing station still in
operation. Another , solution, though not too practical, is to change the
vessel's direction at the dock by 90 degrees every month or so.


"Joe" wrote in message
oups.com...

Bob Crantz wrote:
A magnetic compass is basically useless on a steel boat without the
use of
quadrential spheres.

Does Joe ever get his boat degaussed?

No..Joe has an up to date card with all the TVDMC info needed.

How would Joe check the alignment of his spheres?

By boxing?


What is the common term for the quadrential spheres?

My balls?



Would Joe have to re-align the compass if his boat was hit by
lightning?


No. The lighting bolt would travel thru RedCloud not affecting any
equipment like it would on an in-ferior plasctic boat.


Bob Crantz

Joe