True Course, True Bearing, Relative Bearing. True Course is the direction of travel of the vessel. Also, is the dihedral angle formed between the True Meridian Plane and the Longitudinal Centre Plane of the vessel.
Category: Basic Knowledge
Dividing of Horizon in Compass Points. Dividing of Horizon in Compass Points is no longer used in navigation than for to indicate the approximate directions such as wind direction, current direction, etc.
Dividing of Horizon in Degrees. Conversion. Dividing of Horizon in Degrees is for determining directions at sea and is made in relation to certain plans and main lines.
Dip of the Sea Horizon. Dip, Depression or Inclination of the Visible Horizon (Dip of the Sea Horizon) is the vertical angle between the True Horizon Plane and the direction to the Visible Horizon.
Corrected Visibility Distance. To find out the Corrected Visibility Distance to an object is necessary to apply a correction to the visibility distance given on the charts.
Extreme Range The Extreme Range is the maximum distance at which an object of a given height may be seen at sea.
Distance of the Sea Horizon. Distance of the sea horizon is greater than the geometric distance to the horizon because: Earth’s atmosphere is not all the same density. It is denser at the surface of the earth and decreases with altitude.
Measurement units. The measurement units used in marine are divided into two systems.
Length of one minute of arc of a meridian. Length of one minute of arc of meridian: It is known that a meridian has a form very close to an ellipse.
Departure East – West Departure East – West: is the distance in nautical miles measured on the parallel of average latitude, between the meridian of departure point and the meridian of arrival point, in the navigation on the rhumb line.