Choosing The Right Marine Compass for Your Boat

Marine compasses assist in navigating waters by allowing you to take a magnetic bearing or selecting a magnetic heading to steer your vessel.
Selecting the right for your boat, sailboat or yacht compass depends on a few key factors for your consideration.

What type of compass do you prefer?

Magnetic Compass: This type of compass uses a magnetic card printed with directions and degrees - similar to a needle on a land based compass - which swivels inside a protective case, sometimes suspended in oil or water. This card is set in a gimbal with corrector magnets, which offset any possible interfering magnetism you may have on board, such as speaker magnets or large chunks of ferrous metal such as engine blocks. It is also set in such a way to cancel out movement from the water, which can cause the card to move otherwise.

Electronic Compass: Using the same principles as a magnetic compass, rather than the directional magnet of the compass being attached to the card itself, the sensor is placed remotely on another part of the vessel, preferably far away from the interfering magnetism on board. The signal of direction is sent to the unit which shows the direction your boat, sailboat or yacht is going.

How will you use or read the compass?

Magnetic North is an area on the Earth's surface that all marine compasses are drawn towards.
However, magnetic north is not the same area which is considered to be the same as true north, which would be the North Pole, and the area in which the Earth rotates on its axis.

Depending on the part of the world you are in, the degree of declination changes, as with it, so does the relation between true north and magnetic north on your compass.
Charts can offer declination in which to set your marine compass in order to get an accurate heading.
If accurate headings and bearings aren't made, this will drastically affect your navigation.
On the open water, compasses have been crucial in navigation for centuries.
Certainly, GPS and other navigation methods are available, but compass navigation is still important on the open water.

Marine Compass Mounting Styles for Your Boat

Depending on the type of boat and mounting style you need, there are several different options available.

Surface Compass: One of the easiest ways to mount a compass and useful for a variety of different helm layouts. This mount just sits on a surface and is easily removed.

Binnacle: Also sits on a surface or a steering pedestal, it is useful for watercraft without a lot of room on a mounting surface for flush mounting.

Bulkhead: Looking like other dials and instruments, these are mounted into the bulkhead to match. They are good for visibility and saving space, especially on sailboats.

Bracket: Gives you the ability to mount your compass on a variety of surfaces at varying tilt angles for better visibility.

Flush: Allows you to mount your compass on a horizontal surface in a cutout, with half above and half below the level of the surface.

Proper Compass Installation

Proper installation of your marine compass is vital for accuracy. Boat compasses are precision instruments, and for them to be effective, we recommend following these basic installation procedures:

Visibility is important, especially for the helmsman. Install the compass where it is most comfortable to be seen while at the helm of your boat or yacht.

Since a straight bearing is crucial in navigation, the compass must be aligned with the axis of the bow and stern of the vessel.

Eliminate electrical interference. Wires and electricity also carry magnetic fields which can interfere with your compass. Twisting night light wires around each other can also cancel out interference.

Be aware of nearby metal fittings which may cause interference. This can be determined by "swinging" the compass to test for any deviation that might be present. Corrector magnets within the boat compass can then be used to compensate for any deviation. These corrector magnets, however, are not effective against electrical interference.

Contact us

Defender has the solution to all of your boating needs, including boat, sailboat, and yacht compasses.
Contact us for more information on our products and services for perhaps one of the most important pieces of equipment on your boat, as well as any of your other boating or watercraft needs.