Instrumentation

When properly sized, installed, and compensated a marine compass is the most important instrument on any boat. It will provide accurate, trouble-free heading references under the most adverse conditions without relying on electricity, radio signals, or satellite communications. Quality components aid accuracy, smooth response, stability, and trouble-free operation. The most important criteria when selecting a compass are mounting style, size, readability of the card, and design of your boat. There are five different mounting styles­– dash-mounted, ideal for powerboats with limited dash space; bulkhead-mounted, for sailboats to reduce interference with lines and save space; flush or surface-mounted for compact dashboard designs; binnacle-mounted, featuring a raised outer case with hood; and bracket-mounted on the deck or dash which allows the compass to remain at the proper viewing angle. Dial design is also an important factor as readability is key. The four designs are the direct-read dial, which allows you to see the compass heading and lubber line from directly in front and is great for when the compass is mounted at eye level; the flat-card or open dial, which allows you to look down on the compass to see the course heading; the combi-dial, which incorporates dials that can be read from both above and in front of the compass; and gimbaled compass, which is ideal in rough conditions. In an ideal situation, a compass should be mounted directly in front of the helm, as well as directly above the centerline of the hull. If this is not possible, the compass should be mounted parallel to the centerline. On powerboats with upper steering stations, a compass should be installed at both locations.