Best Boat Guide

by John N. Jamelson

Do you know how to shape the leech of your mainsail for power and drive when close hauled. How can you tell at-a-glance if it's driving the boat ahead--or pushing it more to the side? Learn how to sail a boat better than ever before with this easy 1-2-3 guide on how to shape your mainsail leech to perfection!

Put twist into your mainsail so that the leech "falls off" the wind to produce forward drive. Look at any small cruising or racing sailboat on a close hauled course. What do you notice about the upper half of the mainsail and headsail? If they are trimmed right, each boat sail twists off in the top portion.

Winds near the top of your sailboat mast are higher. Some experts estimate that at just 60 feet off the water, the true wind speed increases by 50% and changes direction by several degrees! Twist helps shape your sail to take advantage of both factors. Follow these three simple steps to success:

1. Sight up the mainsail leech

Set both sails for a close hauled course. Stand behind the mainsail so that you can sight up the leech from the clew to the head of the sail. Does the leech "cup" to windward all the way up to the head of the sail? This causes the sail to stall and drives the boat sideways. Go to the next step to power up your sail for good forward drive.

2. Ease the mainsheet

Ease the mainsheet one or two inches. Stop when you see the leech twist to leeward at about halfway up the sail. Then, check the uppermost mainsail batten. Does it parallel the sailboat boom without any "cock" to windward? Adjust the mainsheet one inch at a time as needed. Do this until the leech and upper batten look just right.

In higher winds, adjust your twist first. Then, slide the mainsheet car down the traveler track to leeward. This will reduce heel, keep the wheel or sailboat tiller light, and provide good power and drive.

3. Check the twist on both sails

Make one final check to see if the headsail and mainsail form an even, parallel slot. Adjust the sheets a bit at a time until you have this just right. Your boat should surge ahead like a wild mustang!

Use these simple secrets to learn how to sail a boat on close hauled courses better than ever before. You will be rewarded with more speed, power, and drive on any small cruising or racing sailboat.