Estimated Position (EP)
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An Estimated Position (EP) in sailing is a calculated position plotted on a chart that accounts for environmental factors like tidal stream and leeway, improving upon a Dead Reckoning (DR) position. It is marked with a triangle around a dot, used when a precise fix is unavailable.
Key Details About EP:
Definition: The most likely position of a vessel between fixes, calculated by adjusting the DR position for current and wind effects.
Plotting: It is marked on the chart as a dot surrounded by a small triangle, with the time noted.
Components: An EP calculation includes the last known position (LKP), intended course, speed, and estimated tidal drift.
Distinction from DR: While DR only uses speed and heading, an EP applies environmental corrections.
Related Term: A "Projected EP" allows sailors to predict their future position based on current heading, expected speed, and predicted tidal currents.
Key Details About EP:
Definition: The most likely position of a vessel between fixes, calculated by adjusting the DR position for current and wind effects.
Plotting: It is marked on the chart as a dot surrounded by a small triangle, with the time noted.
Components: An EP calculation includes the last known position (LKP), intended course, speed, and estimated tidal drift.
Distinction from DR: While DR only uses speed and heading, an EP applies environmental corrections.
Related Term: A "Projected EP" allows sailors to predict their future position based on current heading, expected speed, and predicted tidal currents.