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post #1 of Old 01-29-2003 Thread Starter
Dobbs Davis
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Choosing the Right Headsail

Getting the boat balanced by way of choosing the right headsail for the conditions is as important for safety as it is for performance.

Headsail selection can be one of the most important yet difficult decisions to make while sailing—whether you’re racing or cruising. The wrong sail can have a profound effect on performance and safety. Too big a headsail and the boat becomes overpowered, causing too much heel and excessive helm. Conversely, if the sail is too small, not only will speed and power be reduced, but there may be no feel at all on the helm.

For performance sailors, the proper headsail choice is important not just for windward-leeward racecourses, where your use of the headsail is for optimal upwind performance, but also in distance races where it's important to select the right jib for reaching angles and to know just at which angle and wind speed the spinnaker becomes the more efficient choice. Finally, changing sails while racing is an important skill to master for both efficiency and safety.

Headsail Options    The choice of which jib or genoa to use will obviously depend on what’s available in your boat's sail inventory. If you have only one jib, as in some class of boats (J/105s, Melges 24s, and Folkboats, etc.) then the choice is simple on the water, but perhaps more complex on the dock, particularly if you use a roller-furling headsail. Of course you should choose the sail that will perform best for the weather that you anticipate for the race. For example, a heavier, flatter sail would be better for breezy days, while a lighter, fuller sail would perform better in less wind. If you’re in doubt, the best rule of thumb is generally to err on the part of the fuller sail because it's usually easier to de-power a full sail than to try and power-up one that is too flat.

Larger boats usually carry an ample selection of headsails. The staysail set on this 60-foot Swan is the appropriate choice for the heavy conditions.

For boats that carry a selection of headsails, your sailmaker can usually give you the best indication of what the optimal wind range will be for each and where the crossovers are between them. Most sails are designed and built to perform best within a particular wind range, with some variation is possible depending on the sea state. For conditions in which the seas are choppy and more power is needed, it’s advisable to use the fuller sail toward the top of its range. If the seas are flat, then the flatter sail may be adequate toward the bottom of its wind range. But be aware that taking the lighter, fuller sail up to the top of its range for too long can affect the life of the sail, as the material used to construct the sail is probably inadequate to hold its shape much above the recommended wind range.

As boats get bigger, the racing rules and performance niches permit a greater range of headsail inventories, making the selection process both more critical and complex. On Bob Towse's Reichel/Pugh 66 Blue Yankee, for example, we have three No. 1 genoas—Light, Medium, and Heavy—along a No. 2 (or a No. 1+, so-called because its size approaches that of the Heavy No. 1). We also carry a No. 3, a No. 4, and even a very heavy No. 5 jib for storm conditions. In most of our sailing, however, we usually end up deciding between the various No. 1s, or occasionally between the No. 1+ and the No. 3 if there's consistently more than 20 knots of breeze.

While it can vary greatly between boats, a typical range of selection might be as follows:

3 to 9 knots—Light No. 1
8 to 15 knots—Medium No. 1
14 to 18 knots—Heavy No. 1
17 to 20 knots—No. 2
19 to 24 knots—No. 3.

At around 25 knots of wind, the choices become whether to reef the mainsail or switch to even smaller jibs. Most boats will opt to reef and hoist either the No. 3 jib or even a No. 4 if there is one in the inventory. This decision will ordinarily be dictated by helm balance. If there's excessive weather helm, either reef or put up a larger jib, and if there's neutral or even lee helm, shake out the reef or put up a smaller jib.

"With excessive weather helm, either reef or put up a larger jib, and with  neutral or lee helm, shake out the reef or put up a smaller jib."
When Reaching
    On distance races where the apparent wind angle (AWA) is in the range between 50 to 80 degrees, you may find yourself wishing for another sail because most genoas have been designed for upwind and not reaching performance. Even after you move to an outboard lead to try to prevent the leech from twisting too much at the top of the sail, and after you sag the headstay to give more power, there is still an angle at which the boat will be begging for more power up until the AWA is broad enough to make use of the spinnaker a reasonable option.

It is in this transitional range that there has been tremendous development of specialty sails. The most common new sail is a reaching headsail called a Jib Top, which has the same LP measurement as the No. 1 genoas, but is high-clewed and fuller in shape, so the power in the sail is carried higher and further aft. Jib Tops are great sails to use in the range of about 55 to 75 degrees of apparent wind, but are actually less effective than the genoa in breeze less than about 10 to 12 knots. At higher wind speeds, they can be carried effectively at broader angles until the spinnaker becomes the faster sail.

To help channel the flow of air across the back of the mainsail in these broader AWAs, a genoa staysail can also greatly enhance headsail-reaching performance. This is typically a three-quarter-hoist sail set either on a jib halyard or even a topping lift and tacked on the foredeck centerline about a third of the distance aft from the bow to the mast. As with all staysails, however, the effectiveness of these sails is limited to specific wind speeds and angles; just setting the sail and making the telltales work won’t necessarily make you faster. In fact, it's always a good idea to monitor the boat speed before the setting a staysail and comparing it to the speed after it's been set.

Sails like this Code Zero headsail (seen aboard the VO 60 Amer Sports One) have a tremendous range of use relative to the apparent wind angle.
Another relatively new sail seen with more frequency in the last year or two is the Code Zero. This sail, developed with great success by the EF Language team in the last Whitbread ‘Round the World Race, can best be described as a sort of a hybrid between a spinnaker and a Jib Top. Code Zero sails tack on the bow, but are set on a spinnaker halyard that provides the luff tension. The size of these sails is enormous compared to the Jib Top, since the girth is huge and carried high in the sail plan, like an asymmetrical spinnaker. However, unlike a spinnaker, these sails are typically made of laminate materials like other headsails.

The useful wind range for Code Zeros is typically between that of the Jib Top and the spinnaker, but because of its huge size and power, its effectiveness is sensitive to too much wind. In light air, the Code 0 has a tremendous AWA range and replaces the Jib Top in less than about 12 knots. But this ranges narrows greatly once the breeze increases to where in 15 knots of wind the sail is simply too overpowering.

Headsail Changes    Most performance-oriented boats are equipped with duel-grooved headfoils because this vastly simplifies changing sails as well as making them more efficient. When the conditions call for a sail change, however, there are a few tricks to remember to make the process faster and safer.

The best way to make a change while going upwind is to hoist the new sail in the windward groove of the headfoil with only the weather jib sheet attached. Once the sail is up, the boat can be tacked and the new sail sheeted in while the old sail is dropped on deck. This is called a tack set or a tack change.

This asymmetrical sail is affixed via a tack strop, which will make it easier for the bow crew to attach and hoist the headsail when the time comes.
One problem with the strategy of tack changes, however, often occurs in distance races where the heading to the mark dictates a straight-line course and tacking is not an option. In these situations, the change must take place with either and inside-out, or outside-in technique, depending on the available groove. The easiest maneuver is the inside-out, where the new sail is hoisted in the weather groove inside the old sail. A new sheet is then rove and tensioned to leeward, and the old sail is doused by releasing the sheet and halyard and having the forward crew gather the sail under the foot of the new sail.

The outside-in change is more difficult, since the sail has to be hoisted and fed into the leeward groove under the existing sail. The crew hoisting the new sail has to overcome all the friction associated with bending the two sails around each other. One trick we use on Blue Yankee is to attach a small strop secured through a cunningham hole in the luff of the existing jib to the tack fitting. Once this strop is tensioned, the tack of that sail can be released so that the luff load is now taken up by the strop and the foot of the sail is now much more open to allow the new sail to be fed underneath. Once the new sail is up and the sheet trimmed, it’s simple to douse the old sail since it's now on the weather side.

In breezy conditions and rough seas, it's sometimes faster and safer to perform bald-headed headsail changes. What this simply means is that the crew takes the old sail down and stows it before bending and hoisting the new sail. You should, however, have the new sail on the bow ready to hoist before the old sail is doused so that the halyard can be attached quickly and the maneuver take as little time as possible.

Regardless of what method you use to change headsails, it’s important that you follow a few simple guidelines:
  • Use the pre-feeder so that the luff tape of the new headsail will not tear as it is hoisted into the foil.
  • Make sure the people in the pit who are tailing the halyard watch the bow person carefully so that they don’t lag behind or get ahead of that person.
  • Make sure that the bow person has sail ties handy to contain the old sail so that it won’t slip over the side.
  • Keep as many people as possible focused on sailing the boat and only have the people directly involved in the change working on that project.

Suggested Reading:

Headsail Trimming Basics by Rich Bowen

Shifting Gears in Light and Variable Winds by Rich Bowen

Headsails by Brian Hancock

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