Under the action of the wind, a sailboat doesn't always follow its planned course exactly: it undergoes a lateral deviation which can affect its trajectory and positioning. This deviation, called drift is a fundamental element to master in order to optimize safe and efficient browsing.
What is wind drift?
Visit drift is the angle between the true heading (CV) of the vessel âeuros i.e. the direction you wish to follow âeuros and the route actually followed on the water, surface route or true route (RS or RV) . This difference is caused by the effect of the wind pushing the ship sideways. Drift is expressed in degrees and can be positive (+) or negative (-) depending on which side the ship is pushed.
- Positive drift (+) when the wind pushes the boat to starboard (right).
- Negative drift (-) when the wind pushes the boat to port (left).
A good navigator must be able to anticipate and correct this drift in order to adjust his trajectory and avoid any major deviation from the planned route.
Calculate and correct drift
To estimate drift, it is necessary to know wind direction and the ship's course . Here are two practical examples.
- If a boat follows a true heading 90° (East) and the wind blows from North it can be pushed towards starboard with a positive drift (+5°). The route will then be 95° .
- If a vessel is following a true course 200° (south-southwest) with a wind coming from west the drift can be -4° pushing the boat slightly to port and making it follow a true course of 196° .
An experienced sailor uses these calculations to adjust course and counter the effect of wind by correcting the helm or adjusting the boat's trim. This correction is all the more important when sailing close to the coast, in areas with strong currents, or during precision maneuvers such as entering a port.
Techniques to limit the impact of drift
Several techniques can be used to minimize drift:
- Trim the sails drift: in sailing, a good grip on the wind and the right trim reduce the effect of drift.
- Adopt an adapted drift plan some boats are equipped with a deeper keel than a ballasted dinghy to limit lateral deviation.
- Anticipate and correct in motorized navigation, a slight course adjustment may be enough to compensate for drift and maintain a precise course.
Taking drift into account is essential for safe, efficient navigation, especially on long journeys or in difficult weather conditions.
Whether you're a yachtsman or an experienced skipper, mastering wind drift is essential for optimizing your sailing. Understanding its impact and knowing how to anticipate it enables you to improve your course accuracy and safety at sea. Training is the best way to acquire these reflexes! Grab a pencil, practice on paper, then take the helm, test the influence of the wind on your trajectory and adjust your settings to perfect your technique.
