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Optimize for light air

2017 June 16

Instead of turning on the engine, discover the art and pleasure of coaxing a boat through a small breeze

Sailing in light air is a science and an art. The science comes from adjusting your sails and position of sail to get the maximum lift and momentum. The art is the patience and fortitude for you and your crew to remain still, quiet and aware while resisting the urge to reach for the start button on the “Iron Genny.” With some experimentation and focus, you’ll fine that it’s not difficult to keep the boat moving well in light air, and it can be surprisingly pleasurable sailing too. 

Keeping the boat moving starts with understanding and appreciating the wind. In normal conditions there is more wind at the top of the mast than closer to the water. This fact is especially important when understanding sail trim and twist to maximize the amount of draft in your sails to take advantage of these conditions.

Ease halyards and the backstay to provide some headstay sag, and steer with a light touch to optimize light-air performance.
Paul Todd/Outside Images photo


It’s also important to consider momentum. In light air the best points of sail are around a close reach—45 to 60 degrees to weather. Although it may seem you could point higher, you’ll lose your apparent wind and momentum by trying to point too high. Additionally, you’ll lose the effectiveness of your keel and rudder without enough water moving across them. Pay attention to the nuance of lighter winds, which can be erratic. In your heightened state of awareness, you’ll want to anticipate boat position and trim to capture every breath of wind over your sails.

You have to adjust to the conditions and if you’re on a boat with headsail options, this is the first change you’ll want to make. Choose your lightest headsail. A light genoa is good for light air, but in ghosting conditions a windseeker—an unstayed (freestanding) small foresail that tacks to the deck aft of the forestay and can be hoisted with a spinnaker halyard—is an excellent option. These sails are small and light and will help keep the boat moving. Another great option on a boat with an expansive sail inventory is a Code Zero—a much larger sail that can be flown 60 degrees to weather, but is significantly lighter than a traditional jib or genoa. 

With the sail selection made, think about easing everything. Start with the backstay, which will provide more headstay sag, setting up a means to create more draft in both the foresail and mainsail. Ease both your jib and main halyards until you see a couple of horizontal wrinkles in your sails. On the main, ease the cunningham and vang along with perhaps a couple of inches in the outhaul. Ease your sheets on both sails, but keep your sails full. Bring your traveler to weather and adjust your mainsheet to bring your boom to about the centerline of the boat. This will create sail twist at the top of the sail and draft to power your main.

Don’t underestimate the importance of weight on board. When sailing alone, I’ll sit on the low side and as far forward as I can. With a crew, I’ll position them forward on the leeward side and I’ll helm from the windward side to focus on the boat’s direction and any sign of a wind to prepare for. Heeling the boat, even a little, reduces the wetted surface of the hull, meaning there’s less boat to drag through the water. 

When it comes to sail trim, consider each of your sails independently. The goal is to get a fuller sail by adding twist to the sails. Start with the headsail. Foresail draft was created by easing the backstay, which allowed your foresail to droop a bit to leeward and create more draft. Adjust the sheet tension to get the bottom telltales flying. Once you have the bottom telltales flying, move the jib fairleads aft or forward until you get the uppermost tails flying in this new eased state. With the foresail trimmed, move to the main. For the mainsail, work the sheet and traveler to get the bottom telltales flying. Then, work the vang and topping lift to create enough twist to get the uppermost telltales flying. All this while concentrating on the wind and boat direction to keep your momentum. 

It’s not uncommon to experience wind sheer in lighter air in which there is a significant difference in the wind direction closer to the water than at the top of the mast. There’s no good way to deal with wind sheer, you just have to work through it. Usually it’s best to trim for the direction experienced closer to the water where there is more sail area. Don’t be tempted to go halfway in between the proper trim for near the water and at the top of the mast, which leaves none of the sail working properly. Get the majority of the sail working at its optimum level and trimmed, and do your best with the rest of the sail.

Leeward weight is key to keep this Tartan Ten moving in light air, and the crew doesn’t seem to mind a bit.
Paul Todd/Outside Images photo


Keep in mind that everything has to be done slower and with more finesse when a boat is moving slowly through the water. This goes for moving around the boat, trimming and steering. All rudder movements should be slight and slow. You don’t want to lose the lift generated by the boat’s movement due to adjusting your rudder too much or too quickly. Oversteering is a good way to put the brakes on.

The best way to tackle light air is to actually experience it. Take a day when the winds are exceptionally light and the waves equally so to do a little practice. Learn how your skills and a boat’s sails can keep the vessel moving despite a seeming unremarkable sailing day. Or better yet, the next time you’re sailing and the wind drops, instead of firing up the engine, keep sailing. You’ll experience the peace and solitude that only listening to the sound of water moving across your boat’s hull can give. 

Capt. Brian Earl is a 100-ton USCG Master Captain and the owner of Sea Safaris Sailing School, an ASA School with locations in Illinois and Wisconsin.