In navigation, what do the terms drift and set refer to?

In navigation, what do the terms drift and set refer to?

• A. Drift is the direction of current; set is the wind direction.
• B. Drift is the movement caused by wind/current; set is the direction of the current; together they determine actual movement.
• C. Drift refers to distance traveled; set refers to speed.
• D. Drift is the vessel's name; set is the anchor type.

Answer: (B)

Understanding how wind and current affect a vessel’s path over the ground is what this item is testing. Drift is the movement caused by wind and current acting on the vessel, not the direction of the current itself. Set is the direction toward which that current is pushing the vessel. When you combine drift and set, they determine your actual movement over the ground (your course over ground), which is what you plot on a chart. Even if you head in one direction, wind and current can push you off that line, so you must account for both drift and set to steer toward your intended track. The other statements mix up what drift and set describe—for example, drift is not the current’s direction, and set isn’t speed—so they don’t capture how these factors shape your actual path.

Understanding how wind and current affect a vessel’s path over the ground is what this item is testing. Drift is the movement caused by wind and current acting on the vessel, not the direction of the current itself. Set is the direction toward which that current is pushing the vessel. When you combine drift and set, they determine your actual movement over the ground (your course over ground), which is what you plot on a chart. Even if you head in one direction, wind and current can push you off that line, so you must account for both drift and set to steer toward your intended track. The other statements mix up what drift and set describe—for example, drift is not the current’s direction, and set isn’t speed—so they don’t capture how these factors shape your actual path.