Knowledge of magnetic compass navigation。

The magnetic compass is an instrument used to indicate the course of a ship and observe the position of an object. Its pointing principle is based on the magnetic force of the geomagnetic field on the free magnetic needle, which is "like repels like and opposites attract each other", so that the two ends of the magnetic needle point to the north and south poles of the geomagnetic field, thereby achieving the purpose of pointing. Although modern high-tech navigation instruments are developing rapidly, the magnetic compass is still widely used today due to its reliability and ease of use. It is an essential instrument for ships.
1. The structure of the magnetic compass: Generally, the magnetic compass used in ships is divided into a driving compass and a standard compass. The standard compass is equipped with an azimuth circle to observe the ship's position, the sun and the position of objects. The magnetic compass used in small ships is mainly composed of two parts: a compass fork and a compass base. The compass basin is mainly composed of a basin body, a compass fluid, a liquid filling hole, a compass disk, an axis needle, an axis cap and a compass baseline. The compass base is mainly used to install compass disks, magnetic bars and other calibration equipment and lighting devices. There is a balance ring on the compass pedestal, and the compass basin is placed on the balance ring, so it should always be kept level when in use.
2. Application of magnetic compass in sailing:
(1) Classification by purpose: In sailing, magnetic compass is a necessary basic navigation instrument, and there are the following types: A: For stabilizing board type sailboats, there are two types of fixed driving magnetic compasses installed on the ship, electronic compasses, and handheld compasses for observing the direction of objects. The handheld compasses currently used are handheld magnetic compasses and handheld electronic compasses
B: For keel-type and catamaran large sailboats, whether they are racing or recreational, in addition to the global positioning navigator "GPS", a driving magnetic compass or an electronic compass must be installed.
(2) Main purpose: In sailing, it is generally used to grasp the heading, observe the direction of objects or obstacles, observe and determine the wind direction and flow direction, and select and arrange training and competition venues.
Precautions for use:
The magnetic compass should be installed on the bow and stern line of the ship, and its baseline should coincide with or be parallel to the bow and stern line of the ship. The compass pedestal should be installed flat. Ferromagnetic objects should not be placed around the compass. Whether it is a fixed or handheld compass, the compass body should always be kept horizontal when in use to ensure observation accuracy.