Grade 10 – Nautical Science

November 23, 2020

Cardinal and intercardinal points

In the days of sail it was virtually impossible to steer a course accurately to within a degree. As a result the compass was divided into thirty two equal “points”, each 11¼° wide. The four major points, namely north, south, east and west, are referred to as the four cardinal […]
November 23, 2020

Relative bearings

Bearings can also be expressed in relative terms, ie bearings relative to the ship’s fore and aft centreline. All bearings on the port side will be prefaced with the word “red” and those to starboard, with the word “green”. They will be followed by the angle measured from the bow, […]
December 8, 2020

Compasses

The instrument which is used to measure and display bearings/courses is known as a compass. There are two basic types of compass used at sea: The Gyro compass. The Magnetic compass. On large merchant ships it is not unusual for it to be equipped with two gyro compasses and one […]
December 8, 2020

Variation, magnetic bearings and deviation

Variation Variation is defined as the angle between the true and magnetic meridians. It is said to be easterly if the direction of magnetic north lies to the east of the true meridian and westerly if it lies to the west. Variation can b e obtained from a special isogonic […]
December 8, 2020

Compass bearings

Compass bearings The angle between the direction of a place or object and compass north is called the compass bearing.  As previously stated it is distinguished by the suffix (C) after the bearing.  Like true and magnetic bearings it is written in three figure notation.  In order to change a […]