Even though most genoas and jibs are smaller than the main- sails they team up with, your head- sail should get at least as much careful trimming attention as your main. That’s because a jib feels no disturbance from the mast and sails in an eternal lift created by flow around the main. As a result, your headsail provides more than its share of your boat’s power.
For these reasons, it’s important to work hard at finding the fast settings for your jib controls. Before every race, talk with the mainsail trimmer and helmsperson. Ask them to check out your jib trim and make suggestions. Talk with them about communication. Then follow the trim ideas here.
Trimming rules of thumb
Unless you are extremely confident about trimming the jib, stick with some proven trimming guidelines that can help you through almost any situation. Here are some things to keep in mind.
Calibrate Always use reference marks to help measure and record fast trim settings. Number the jib track holes for your lead position; put marks near your spreader tips to help gauge leech position; add an easy-to-see reference mark on your jib sheet; calibrate halyard tension; and so on. These are key for being able to reproduce your settings when you have similar conditions again in the future.
Communicate Since the jib trimmer must adjust sheet tension continually for changes in the wind, keep communicating with the helmsperson and mainsail trimmer about what you are doing. If you ease the jib slightly to power up, for example, tell the skipper something like, “I can trim in two inches when you’re ready.” Or if you need more or less headstay sag, negotiate with the mainsail trimmer about how much to adjust the backstay.
No matter what type of boat you sail, there are three important trimming rules of thumb for your jib. First, you must trim the jib so it works with the mainsail. Second, keep adjusting jib trim to match changes in the wind and water. And third, the only valid way to judge whether you are trimming the jib well is by comparing your performance to that of nearby boats. Photo courtesy of Clagett Sailing
Steering Use your jib trim (in conjunction with mainsail trim) to help steer the boat. If you want the boat to turn toward the wind, ease the jib sheet. This reduces wind pressure on the jib and allows the bow of the boat to head up more easily. One example of this happens when the boat gets a lift. If the jib trimmer quickly eases the sheet, it will be easier for the helmsperson to head up into the lift. Conversely, trimming the jib sheet helps push the bow away from the wind.
The ‘groove’ If your skipper is having a hard time finding or staying in the upwind groove (which is common in shifty winds or bumpy seas), make the groove wider with a fuller and more draft-forward headsail. Even though this may sacrifice some pointing ability, it should improve overall performance by increasing the time you are able to sail fast in the groove.
Sheet trim In general, trim the genoa sheet until the curve (twist) in the leech matches the curve in the deepest part of the main. If your jib has battens, it’s usually good to trim the sheet until the top batten is roughly parallel to the boat’s centerline. It may help to put a piece of dark tape on each side of this batten so you can see it more clearly.
Trim guides There are two other good references for jib trim. When it’s hard to see the top of the jib while racing, use the position and shape of the sail’s foot. The distance from your spreader to the sail is also a great reference for duplicating fast trim settings. ■
Look for more of Dave’s headsail trimming tips in our April edition.
This article originally appeared in David Dellenbaugh’s Speed & Smarts, The newsletter of how-to tips for racing sailors. If you want to sail faster and smarter, log onto SpeedandSmarts.com.
A resident of Easton, CT, Dellenbaugh was tactician and starting helmsman for America3’s successful defense of the America’s Cup in 1992. He’s a Lightning World Champion, two-time Congressional Cup winner, seven-time Thistle National Champion, two-time winner of the Canada’s Cup, three-time Prince of Wales U.S. Match Racing Champion, and a winner of the U.S. Team Racing Championships for the Hinman Trophy.
