Sailing Navigation Techniques

Navigating is one of the skills you will learn on a sailing trip. But like all aspects of sailing navigation has its own terminology. Below are some basic terms and definitions as well as in depth information about navigation calculations and techniques.

Bearing - A compass reading or line that describes the direction of an object relative to the boats position.

COG - "Course Over Ground" is the direction of actual travel over the sea floor.

Course - The specific direction from where you are to where you want to go.

DR - "Dead Reckoning" is a theoretical position based on time, course and speed from a known point.

EP - "Estimated Position" is the navigator's best guess of the boats position based on a DR plot and one or more of the following: set and drift calculations, soundings, a single LOP or a running fix.

Fix - The boat's position established at a specific time with a high degree of accuracy.

Heading - The direction in which the boat is pointing.

Isobath - An underwater contour line: a line that connects areas of equal depth.

LOP's - "Lines of Position" are derived from either a range or a bearing. An LOP gives you no a point position, but a line on which you could be anywhere. Two LOP's that intersect give you a weak fix and three give you a very positive fix. By themselves, they can provide useful negative informations.

Plot - Notations on the chart showing the boat's course and speed.

Range - A bearing that intersects two objects and the viewer's eye, for example, a nun with a lighthouse directly over it in the background. An LOP may be plotted without taking a bearing.

More Sailing Navigation Information

Get a Free Catalog