Glossary
Marine navigation has its own secret language, and let’s face it—half of it sounds like someone making things up after too much grog. You’ve got your 'dead reckoning,' which isn’t nearly as ominous as it sounds, and 'bearing,' which has nothing to do with polar bears but everything to do with pointing the right way. Don’t even get us started on 'knots'—why measure speed like you’re tying a shoelace? And then there’s 'fix (not for your engine) and 'DR' (spoiler: it’s not a doctor). If you’re baffled, don’t worry—we’re here to help you decipher this nautical code so you can sound like a pro, not a landlubber who’s lost their compass.
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TermDefinition
- General Nautical Terminology, Navigation APEM More Details
- General Nautical Terminology, Navigation Appraise, Plan, Execute, Monitor (APEM) More Details
- General Nautical Terminology, Navigation Bearing
The direction or angle between a reference point, typically true north, and an object or destination, usually expressed in degrees.
A bearing...
More Details - General Nautical Terminology, Navigation Bearing to Waypoint (BTW)
The direction from a vessel's current position to a predetermined navigational point or waypoint.
In marine navigation, Bearing to Waypoint is...
More Details - General Nautical Terminology, Navigation BTW
The direction from a vessel's current position to a predetermined navigational point or waypoint.
In marine navigation, Bearing to Waypoint is...
More Details - Navigation CADET
The CADET mnemonic can help remember the corrections needed when converting between True North and Compass North bearings. It assists in...
More Details - General Nautical Terminology, Navigation, Safety CBDR
A navigational situation where two vessels maintain the same relative bearing to each other while the distance between them diminishes, often...
More Details - General Nautical Terminology, Navigation Chart
A detailed map used in marine navigation, showing water depths, hazards, and other critical information for safe passage.

A marine chart...
More Details - General Nautical Terminology, Navigation Chronometer
A highly accurate timekeeping instrument, specifically designed for determining longitude at sea.
A chronometer is a precision timepiece used...
More Details - General Nautical Terminology, Navigation Closest Point of Approach (CPA)
Used primarily in maritime and aviation contexts to describe the shortest distance that will be achieved between two moving objects, such as...
More Details - General Nautical Terminology, Navigation Cocked Hat
The small triangular area formed when three position lines on a nautical chart intersect but do not meet at a single point, indicating a degree...
More Details - General Nautical Terminology, Navigation COG
The actual path a vessel follows over the surface of the Earth, as opposed to its heading or intended course.
Course Over Ground (COG) is a...
More Details - Navigation Compass Add East for True (CADET)
The CADET mnemonic can help remember the corrections needed when converting between True North and Compass North bearings. It assists in...
More Details - General Nautical Terminology, Navigation Compass Rose
A circular diagram on nautical charts and compasses that displays directions relative to true north and magnetic north, often including...
More Details - General Nautical Terminology, Navigation, Safety Constant Bearing, Decreasing Range (CBDR)
A navigational situation where two vessels maintain the same relative bearing to each other while the distance between them diminishes, often...
More Details - General Nautical Terminology, Navigation Contour Line
A line on a nautical chart that connects points of equal depth below the water's surface, representing the underwater topography.
A contour...
More Details - General Nautical Terminology, Navigation Coordinated Universal Time (UTC)
The primary time standard by which the world regulates clocks and time serving as the basis for civil time globally.
Coordinated Universal...
More Details - General Nautical Terminology, Navigation, Weather (Meteorology) Coriolis Effect
The apparent deflection of moving fluids, such as air or water, caused by the Earth's rotation, influencing large-scale ocean currents and wind...
More Details - General Nautical Terminology, Navigation Course Over Ground (COG)
The actual path a vessel follows over the surface of the Earth, as opposed to its heading or intended course.
Course Over Ground (COG) is a...
More Details - General Nautical Terminology, Navigation CPA
Used primarily in maritime and aviation contexts to describe the shortest distance that will be achieved between two moving objects, such as...
More Details

