Lee helm

A "lee helm" is a situation in sailing where a sailing vessel has a tendency to turn downwind (away from the wind) and the helm must be constantly corrected by applying pressure towards the wind (to windward) to maintain a desired course.

In other words, the tiller or wheel needs to be pushed or turned to windward in order to prevent the boat from turning downwind. This contrasts with weather helm, where the boat tends to turn into the wind.

Lee helm is generally considered undesirable because it indicates an imbalance in the forces acting on the hull and sails. It can result in:

• Increased drag: The constant rudder correction creates drag, slowing the boat.
• Difficulty steering: Maintaining a straight course requires more effort from the helmsman.
• Potential instability: In extreme cases, lee helm can lead to an uncontrolled jibe.

Causes of lee helm can be varied, but often involve:

• Center of effort of the sails being too far forward: This can occur if the mainsail is too full or the headsail is too small, or if the mast is raked too far forward.
• Center of lateral resistance being too far aft: This is often related to hull design or loading.
• Incorrect trim: Improper sail trim can exacerbate lee helm.
• Weight distribution: Improper weight distribution aboard the vessel.

Corrections for lee helm typically involve adjusting sail trim (e.g., reefing the mainsail, increasing headsail size, adjusting sail draft), adjusting the mast rake, or redistributing weight. Understanding the underlying cause is crucial for effective correction.