In nautical terms, drift refers to the speed at which a vessel, object, or water mass is carried along by currents or wind, typically measured in knots. It represents the magnitude of external forces pushing a boat off its intended course, paired with "set" (the direction) to determine total displacement.

Key Aspects of Drift
Speed Component: While "set" is the direction the current flows, "drift" is the speed of that current (e.g., 2 knots eastward).

Vessel Movement: It describes how far a boat is pushed off its planned track due to wind and current, often used interchangeably with the distance of displacement.

Adrift: A ship is described as "adrift" when it is not under power or control, moving solely at the mercy of the wind and sea.

Leeway vs. Drift: While similar, drift usually refers to the speed of the water current itself, whereas leeway specifically refers to the sideways movement of a ship pushed by the wind.

Contextual Usage
Navigation: Mariners calculate set and drift to make course corrections, ensuring the vessel reaches its destination despite environmental forces.

Search and Rescue: Used to predict the movement of a person or object in the water.