Tips to Ease Your Mainsheet for Speed

Originally published in Sailing World.

One rule of thumb is to ease your sheets when you are feeling slow, but the goal should be to never get slow. Getting to full speed can be simple, but maintaining that momentum is a different story.

During one race at the European Championships in Estonia, I rounded the leeward gate ahead of a group. Another competitor rounded right behind me, dove a couple of boat lengths to leeward into a clear lane, and within 30 seconds of choppy and gusty chaos he sailed all the way in front of me and started pinching me off. Until then I had no idea it was possible to make so many mistakes in such a short distance. The biggest mistake was too much mainsheet tension at the wrong time.

Whether you are sailing through a gust, lull, pinching, footing, or through chop, knowing when to ease your mainsheet can give you a big edge.

Ease when footing

Sails require airflow traveling to leeward of the sail to reach optimal sail force. Feeling and acknowledging this flow lets you focus on keeping the backside of the sail working. When airflow detaches from the back of the sail, it is called stalling.

One major indicator of stalling is when leeward telltales fly straight up or forward. This happens after other parts of the sail have already stalled. Most commonly, the top quarter of the sail stalls first. By the time you see it visually, you have already lost the optimal sailing angle.

I often see this with people who like to foot, sailing slightly below close-hauled. The windward and leeward telltales may look perfect, but other parts of the sail have already stalled. In lighter conditions, detachment is even more common. When you see the leeward telltales not streaming across the sail, ease the sheet first to get the sail producing optimal force and attachment, then head up to your angle.

Avoid stalling any part of the sail. In my ILCA, I like to see the windward telltale dancing downward about 50 percent of the time. This indicates that I am sailing high enough not to stall, but not so high that I am pinching.

Ease after pinch

If you sail into a header and are not quick enough to react, it does not take long for luffing at the front of the sail and the growing separation bubble on the luff to slow you down. Everything seems to point toward pulling the sail in tighter to get rid of the luff and optimize for the higher angle.

But once you establish that your course is too high and adjust back down to your optimal upwind angle, your boatspeed is slower than a boat that never pinched. That pulls apparent wind aft. Easing the sheet momentarily relieves the stall induced by being slow. Then trim to the new apparent-wind angle until you are back up to speed.

Drag comes easy

There are two components of drag when sailing: underwater drag from hull friction, increased by chop and swell; and drag from a sail setup that is too deep with excessive leech hook. Once the boat reaches top speed and apparent wind moves forward, trimming the sail with less leech hook decreases drag in some conditions.

In moderate wind, keeping some hook can help power through chop. In light wind, drag slows the boat and causes apparent wind to shift aft. By the time you notice the leeward telltale standing upright, the sail has stalled and already lost significant force.

Sheeting out before the boat slows maintains force in the sail and helps you stay at speed. In windier conditions, this stalling is perceived in the helm as a lift. Immediately after the bow hits a wave, apparent wind moving aft heels the boat and gives a feeling of heading up. In most conditions, this weather helm says you have slowed and have potential for more speed. Ease the mainsheet for the new apparent-wind direction as part of re-acceleration.

Ease in the gusts

Properly easing the mainsheet into a gust can be the biggest contributor to improving speed. Gusts are indicated by heel. The boat heels as true wind force increases and pulls apparent wind aft.

Resist treating the puff as a lift. It is tempting to point the bow closer to the wind instead of accelerating, but soon after reaching the new apparent close-hauled course, the sail indicates pinching. Instead, ease the main when the puff initially hits, trimming the sail to the new apparent-wind direction.

Lulls and the ease

When sailing into a lull, apparent wind moves forward. This is indicated by the sail luffing, windward telltales dancing, or an obvious loss in power. A header usually has a bigger impact on luffing the sail; in a header, bear away to maintain flow across the windward side of the sail. Do not automatically bear away in a lull.

In boats that carry momentum, you can sail into a lull and momentarily sheet on, blading the sail to reduce drag as apparent wind moves forward. After slowing, apparent wind shifts aft and requires a more forgiving setup. On dinghies where mainsheet affects mast bend, sheet out to increase camber in the top of the sail. On boats where it affects leech twist, ease the mainsheet to open it and increase velocity across the leeward side of the top of the sail.

Stay active with the mainsheet. Ease it for optimal sail force and apparent-wind direction changes. The boat is most affected when these things happen and we do not see them, or are late to react.