The magnetic compass has been with us on the water for a thousand years or so. Recently, though, it has often been overshadowed by the near magic of GPS. For the serious sailor, however, it is the most basic and the most essential navigation instrument. When all else fails—the engine, the electrical system or the GPS itself—the compass still works, showing us the way to safety.

The availability of spare parts and service facilities for compass maintenance is becoming a problem. On Dec. 18 of last year, one of the major U.S. manufacturers notified dealers that it would cease production and support as of Jan. 1. Danforth, a mainstay of yacht navigation for more than half a century, has exited the compass business. Employees were laid off at the start of the normal two-week Christmas shut-down of the company’s plant in Gloucester, Mass.

Most compass repair facilities received leaked information about the pending closure several months ago and stocked up on parts. Negotiations are now underway to establish a source of aftermarket parts through a highly regarded shop in southern New England.

Danforth is not the first compass brand to disappear in recent years. Market conditions in the mid-1980s drove a consolidation of Danforth and the Aqua Meter brand, which were purchased by Rule Industries. The Aqua Meter models were incorporated into the Danforth line, and Rule was later purchased by ITT Industries, the current owners. Then Airguide eliminated all its large compass models in 1993. Three years later, its production was moved to Mexico and parts support was eliminated.

The John E. Hand and Sons Co., which had manufactured compasses since 1873, stopped making small boat compasses in the 1970s but continued with Navy and commercial production. But demand from the commercial and military sectors declined over time, and the company closed its doors in 1997.

The good news is that the oldest and best quality manufacturer remains strong and able to outfit our boats. In 1842, an American college professor named Elbert S. Ritchie invented the expansion mechanism for magnetic compasses. The addition of this flexible diaphram allowed compasses to be filled with fluid and made them more readable and reliable.

Previously, boats used either dry compasses or partially filled compasses to allow for expansion. The resultant condensation on the compass glass was a problem, as was the sloshing fluid (it was also harder to detect the occasional drainage of alcohol by resourceful sailors). Professor Ritchie formed E.S. Ritchie & Sons in 1850. After 117 years, the family sold the company to the Marine Compass Co. of Boston, merging the two companies under the Ritchie name.

Ritchie produces the world’s most popular pedestal-mount compass for sailboats, the SP-5 Globemaster. This stainless steel, binnacle-mounted device has been the compass of choice for most offshore boats built in the U.S. The same basic compass, in other mountings, is used on recreational powerboats and many workboats. Quality is an obsession at Ritchie. While Danforth abandoned brass for plastic construction in 1979, Ritchie continued making the Globemaster in brass until 1990.

I have been impressed by the integrity of the Ritchie organization. In the 1990 change-over to plastic construction, the expansion diaphragm was changed from metal to rubber, as used by most other manufacturers. But a problem was discovered in the fall of 1995 – the rubber began to deteriorate through contact with the compass fluid. In two months, a replacement part was engineered and produced, and a service bulletin was circulated to repair shops, indefinitely extending the warranty to address this problem. The extended warranty program was maintained for 14 years, ending in September 2009. Some compasses serviced under the program in 2009 were 19 years old. That’s integrity!

For the traditional boat, one maker of flat-top, externally gimballed compasses remains in the U.S. Our own Dirigo Compass Co., located in Bellevue, Wash., is still making the solidly built compasses it has produced since 1907. Most find their way onto workboats, particularly to drive autopilots. The compasses are hand-built of copper and brass with plastic top ring and gimbal, and bronze ringsets are available for the classic yacht market.

The compass market is surprisingly diverse. International companies include C. Plath of Germany, Suunto of Finland, Plastimo of France and Major of the U.K. Suunto and Plastimo are reasonably priced. C. Plath and Major are world-class instruments and priced accordingly—remember, too, when you buy the Mercedes, you must also buy the Mercedes parts.

Most boats come with a compass supplied by the builder or outfitting broker, and we expect it to work properly out of the box. Most do. With good care, a quality compass can be expected to provide 10 to 15 years of service before needing maintenance. A proper commissioning will include a compass adjust or compensation (often referred to as “swinging”), but some do not and significant deviation will remain in the compass. If you’re not cruising on the open ocean, a small deviation will have little impact on navigation or safety.

The bottom line is this: take care of your compass. Keep it covered when not in use. If it has a bubble, is discolored or is hard to read, take it to a qualified repair shop. After major repairs, when installing a new compasses or when errors are noticed, contact a compass adjuster. Major changes to the boat, such as a new engine, will also require a compass adjustment.

Bill Haimes operates Island Marine Instrument Co, a compass repair shop in Everett, Wash., and also works as a compass adjuster on vessels of all types. He is a dealer for all the compasses mentioned above, but has no direct financial interest in the manufacturers. He provides some hourly consulting work to Dirigo.