A type of florescent light ballast that uses a magnetic core to regulate the voltage of a florescent lamp.

The bearing of an object after magnetic variation has been considered, but without compensation for magnetic deviation.

The course of a vessel after magnetic variation has been considered, but without compensation for magnetic deviation.

Compass error. The difference between the reading of a compass and the actual magnetic course or bearing due to errors in the compass reading. These errors can be caused by metals, magnetic fields and electrical fields near the compass. The act of checkin ...

The direction to which a compass points. Magnetic north differs from true north because the magnetic fields of the planet are not exactly in line with the north and south poles. Observed differences between magnetic and true north is known as magnetic var ...

The difference between magnetic north and true north, measured as an angle. Magnetic variation is different in different geographic locations, so the nearest compass rose to each location on a chart must be used.

The direction, with respect to magnetic north, from which the wind is blowing. Distinguish from true wind direction.

Naturally occurring magnetic oxide of iron (Fe3O4).

A cup anemometer with its shaft mechanically coupled to a magneto.

A recording magnetometer.

General name for an instrument which measures the earth's magnetic field intensity.

The term "mAh" means "milliamp hours"; it is on most rechargeable battery labels. It refers to the amount of time you can expect a fully charged battery to last. For example, if the battery label states "2,400 mAh," it means the battery can power a device ...

Marine Accident Investigation Branch

First voyage of a ship.

The tallest mast; the forward mast of a yawl or ketch; the mast furthest aft on a schooner

A topsail on the main mast.

The principal sail that is set on the main mast.

The line that controls the angle of the mainsail in its relation to the wind.

Hoisting the ensign at 8 a.m. and down at sunset.

To attach a line to something so that it will not move.