Dog,
re the main
compass on a steel boat....
Billy Ruff'n uses a standard Plastimo yacht
compass without the steel balls. It' works fine -- I had it swung by a professional in Honolulu when I got a new one (old one caught the French champagne disease ... tiny bubbles) and the deviation was only a couple of degrees on some headings and zero degrees on others. I think it's a different story when the
compass is located in a bridge house that's basically a steel box. Our
compass installation is identical to those found on fiberglass boats.
The calibration of an electronic
compass that Plumper mentions above is a standard procedure for electronic
compass calibration. It's done when any new electronic
compass is installed (regardless of hull construction) and consist of running the boat in slow circles until the
compass figures out what's up.