Set and Drift is the difference between your dead reckoning position and your actual position caused by what?

Set and Drift is the difference between your dead reckoning position and your actual position caused by what?

• A. Weather
• B. Navigation errors
• C. Time of day
• D. Currents and seas

Answer: (D)

Set and drift describe how water movement affects your path. Dead reckoning uses your heading, speed, and time to estimate where you should be, assuming the vessel follows that line exactly. But currents push the boat sideways and/or forward, so your actual position ends up off from the dead reckoning position. The set is the direction the current is moving you, and the drift is how far the current carries you. Currents and seas are the direct cause of this difference, whereas time of day isn’t a factor and weather only influences currents indirectly. To account for it, navigators check fixes and adjust their course for the current as needed.

Set and drift describe how water movement affects your path. Dead reckoning uses your heading, speed, and time to estimate where you should be, assuming the vessel follows that line exactly. But currents push the boat sideways and/or forward, so your actual position ends up off from the dead reckoning position. The set is the direction the current is moving you, and the drift is how far the current carries you. Currents and seas are the direct cause of this difference, whereas time of day isn’t a factor and weather only influences currents indirectly. To account for it, navigators check fixes and adjust their course for the current as needed.