Boat handling
What Is Weather Helm? Causes and How to Reduce It
Published · Last checked October 2026
Weather helm is a sailing boat's tendency to turn up into the wind if you let go of the tiller or wheel. You feel it as a steady pull, and you have to hold the tiller slightly to windward to sail straight. A few degrees of weather helm is good: it gives feel and means the boat rounds up safely if the helmsman lets go. Too much slows you and can cause a broach. Reduce it by easing the main, flattening sails, reefing and sailing more upright.
What causes weather helm
A boat pivots around its underwater centre of lateral resistance (CLR), roughly the keel. The sails push from their centre of effort (CE). When the CE sits aft of the CLR, or the drive from the sails is offset to leeward as the boat heels, the boat wants to rotate into the wind. Main causes:
- Heel: the most common cause. As the boat heels, the sails' push moves outboard to leeward and the hull shape becomes asymmetric, both turning the bow to windward.
- Too much mainsail relative to the headsail, or a full, tight-leeched main.
- Headsail reefed or furled before the main, moving the CE aft.
- Mast rake too far aft, or crew weight too far forward.
How to reduce weather helm
| Action | Why it helps |
|---|---|
| Ease the mainsheet or drop the traveller | Spills wind from the main, reduces heel |
| Tighten the backstay, outhaul and cunningham | Flattens the main and opens the leech |
| Ease the kicker in gusts | Lets the top of the main twist off |
| Reef the main first | Moves the CE forward and reduces heel |
| Move crew weight to windward | Keeps the boat flatter |
If the boat is heeled more than about 20 to 25 degrees and you need lots of helm, it is almost always time to reef. Read when to reef.
Lee helm and neutral helm
Lee helm is the opposite: the boat wants to bear away, and you hold the tiller to leeward. It can be dangerous, because if you let go the boat speeds up and heads downwind. It usually appears in very light winds or with too much headsail. A neutral helm needs no correction but gives little feel. Most designers aim for a light weather helm of around 3 to 5 degrees of rudder.
Why a little weather helm is good
The rudder angled slightly to leeward acts like a small foil and adds lift to windward, helping the boat point. More importantly, if the helmsman falls or lets go, the boat luffs up and stops rather than charging off downwind. Too much rudder angle, though, acts as a brake and stalls the rudder, which is how broaches start.