Navigation and Seamanship

1.3.3.2. Important DR Terminologies

Heading (Hdg) (SH)

Horizontal direction in which a ship points or heads at any instant, expressed in angular units, clock wise from 000^o through 360^o from a reference direction. The heading of a ship is also called ship’s head.

Heading is a constantly changing value as a ship oscillates or yaws across the course due to the effects of the sea and of sterring error.

Course (C)

The direction is which a vessel is to be steered or is being steered; the direction of travel through the water. The course is measured from 000^o clockwise from the reference direction to 360^o. Course may be designated as true, magnetic, and compass or grid as determined by the reference direction.

Course line

Graphic representation of a ship’s course.

Fix

A position established at a specific time to a high degree of accuracy.

Running fix is a position of lesser accuracy lased in part on present information and in formation transferred from a prior time.